JP6918184B2 - Bicycle rear hub assembly - Google Patents

Description

The present invention relates to a bicycle rear hub assembly.

Biking is becoming an increasingly popular form of recreation as well as a means of transportation. Riding a bicycle is also popular as a competitive sport for both professionals and amateurs. Various bicycle parts are constantly being improved in the bicycle industry, regardless of recreational, mobile or competitive use. One of the bicycle parts that has been widely redesigned is a hub assembly (see, for example, Patent Document 1).

U.S. Pat. No. 8,820,852

A technical challenge disclosed in the present application is to improve the durability of the sprocket support and / or to increase the degree of freedom in selecting the material of the sprocket support without reducing the durability of the sprocket support. be.

According to a first aspect of the invention, the sprocket support rotatably mounted on the hub axle of the bicycle rear hub assembly comprises at least 10 outer spline teeth and a plurality of outer helical spline teeth. At least 10 outer spline teeth are configured to engage the bicycle rear sprocket assembly. The plurality of outer helical spline teeth are configured to engage the freewheel mechanism. Each of the at least 10 outer spline teeth has an outer spline drive surface and an outer spline non-drive surface for receiving a drive rotational force from the bicycle rear sprocket assembly during pedaling. The outer spline drive surface includes a radial outermost rim, a radial innermost rim, and a radial length defined from the radial outermost rim to the radial innermost rim. The total radial length of the outer spline drive surfaces of at least 10 outer spline teeth is 7 mm or more. The outer spline crest diameter of at least 10 outer spline teeth is smaller than the crest diameter of the plurality of outer helical spline teeth.

In the sprocket support according to the first side surface, the rotational force acting on each of at least 10 outer spline teeth is increased by at least 10 outer spline teeth as compared with the sprocket support including 9 or less outer spline teeth. It will be reduced. This increases the durability of the sprocket support and / or increases the degree of freedom in selecting the material of the sprocket support without reducing the durability of the sprocket support.

According to the second side surface of the present invention, in the sprocket support according to the first side surface, the outer spline drive surface is the radial direction of the outer spline drive surface and the outer spline drive surface from the rotation center axis of the bicycle rear hub assembly. It has a first lateral spline angle defined between and a first radial line extending to the outermost periphery. The first outer spline surface angle is 6 degrees or less.

In the sprocket support according to the second side surface, the strength of the outer spline drive surface can be increased.

According to the third aspect of the present invention, in the sprocket support according to the first or second side surface, the outer spline non-driving surface is the outer spline non-driving surface and the outer spline non-driving surface from the rotation center axis of the bicycle rear hub assembly. It has a dihedral spline angle defined between and a dihedral line extending to the outermost radial edge of the drive surface. The dihedral spline surface angle is 6 degrees or less.

In the sprocket support according to the third side surface, the strength of the outer spline drive surface can be increased.

According to the fourth aspect of the present invention, in the sprocket support according to any one of the first to third aspects, at least one of at least 10 outer spline teeth has a spline tooth axial length of 27 mm or less. be.

In the sprocket support according to the fourth aspect, the weight of the sprocket support can be reduced.

According to the fifth aspect of the present invention, in the sprocket support according to any one of the first to fourth aspects, the total number of at least 10 outer spline teeth is in the range of 22 to 24.

In the sprocket support according to the fifth aspect, the total number of at least 10 outer spline teeth improves the productivity of the bicycle rear hub assembly while improving the durability of the sprocket support.

According to the sixth aspect of the present invention, in the sprocket support according to any one of the first to fifth aspects, at least 10 outer spline teeth are different from the first outer pitch angle and the first outer pitch angle. It has a second outer pitch angle.

In the sprocket support according to the sixth side surface, the bicycle rear sprocket assembly can be easily attached to the bicycle hub assembly at the correct circumferential position.

According to the seventh aspect of the present invention, in the sprocket support according to the sixth aspect, the first outer pitch angle is in the range of 13 degrees to 17 degrees. The second outer pitch angle is in the range of 28 degrees to 32 degrees.

The sprocket support according to the seventh aspect facilitates the bicycle rear sprocket assembly into the bicycle rear hub assembly in the correct circumferential position while improving the durability of the sprocket support and the productivity of the bicycle rear hub assembly. Can be installed.

According to the eighth aspect of the present invention, in the sprocket support according to the sixth or seventh aspect, the first outer pitch angle is half of the second outer pitch angle.

In the sprocket support according to the eighth side surface, the bicycle rear sprocket assembly can be easily attached to the bicycle hub assembly at the correct circumferential position.

According to the ninth aspect of the present invention, in the sprocket support according to any one of the sixth to eighth aspects, the first outer pitch angle is in the range of 13 degrees to 17 degrees.

In the sprocket support according to the ninth side surface, the durability of the sprocket support is improved while improving the productivity of the bicycle rear hub assembly at the first outer pitch angle.

According to the tenth aspect of the present invention, in the sprocket support according to any one of the first to ninth aspects, the total radial length of the outer spline drive surface is in the range of 11 mm to 14 mm.

In the sprocket support according to the tenth aspect, the strength of the sprocket support is increased while improving the productivity of the bicycle rear hub assembly in the overall length in the radial direction.

According to the eleventh aspect of the present invention, in the sprocket support according to any one of the first to tenth aspects, at least one of at least 10 outer spline teeth is at least 10 outer from the center of rotation. It is symmetric in the circumferential direction with respect to the reference line extending in the radial direction with respect to the center axis of rotation to the circumferential center point of the outermost peripheral end in the radial direction of at least one of the spline teeth.

In the sprocket support according to the eleventh aspect, the productivity of the sprocket support can be improved.

According to the twelfth aspect of the present invention, the outer spline crest diameter is 34 mm or less in the sprocket support according to any one of the first to eleventh aspects.

With the sprocket support according to the twelfth side surface, the weight of the bicycle rear hub assembly can be reduced.

According to the thirteenth aspect of the present invention, the outer spline crest diameter is 33 mm or less in the sprocket support according to any one of the first to twelfth aspects.

The sprocket support according to the thirteenth aspect can further reduce the weight of the bicycle rear hub assembly.

According to the 14th aspect of the present invention, the outer spline crest diameter is 29 mm or more in the sprocket support according to any one of the 1st to 13th aspects.

In the sprocket support according to the 14th side surface, the strength of the sprocket support can be ensured.

According to the fifteenth aspect of the present invention, in the sprocket support according to any one of the first to fourth aspects, the outer spline valley diameter of at least 10 outer spline teeth is 32 mm or less.

In the sprocket support according to the fifteenth side surface, the radial length of the drive surface of at least one outer spline tooth can be increased in the outer spline valley diameter. This increases the strength of the sprocket support.

According to the 16th aspect of the present invention, the outer spline valley diameter of the sprocket support according to the 15th aspect is 31 mm or less.

In the sprocket support according to the 16th side surface, the radial length of the drive surface of at least one outer spline tooth becomes longer in the outer spline valley diameter. This increases the strength of the sprocket support.

According to the 17th aspect of the present invention, in the sprocket support according to the 15th or 16th aspect, the outer spline valley diameter is 28 mm or more.

In the sprocket support according to the 17th side surface, the strength of the sprocket support can be ensured.

According to the eighteenth aspect of the present invention, the bicycle rear hub assembly includes a hub axle, a hub body rotatably mounted on the hub axle around the center of rotation of the bicycle rear hub assembly, and the first to seventh side surfaces. The sprocket support according to any one of the above is provided.

In the bicycle rear hub assembly according to the eighteenth aspect, the durability of the sprocket support is improved and / or the degree of freedom in selecting the material of the sprocket support is increased without reducing the durability of the sprocket support. ..

According to the 19th aspect of the present invention, the bicycle rear hub assembly according to the 18th aspect further includes a freewheel mechanism. The freewheel mechanism comprises at least one second ratchet member including at least one first ratchet tooth and at least one second ratchet tooth configured to engage at least one first ratchet tooth to transmit torque. Includes a second ratchet member, including ratchet teeth. The first ratchet member is configured to engage one of a plurality of outer helical spline teeth of the hub body and sprocket support to transmit torque. The second ratchet member is configured to engage the other of the plurality of outer helical spline teeth of the hub body and sprocket support to transmit torque. At least one of the first ratchet member and the second ratchet member is movable with respect to the hub axle in the axial direction with respect to the center of rotation.

In the bicycle rear hub assembly according to the nineteenth side surface, the drive efficiency of the bicycle hub assembly can be improved and the freewheel mechanism can be reduced in weight.

The techniques disclosed in the present application can improve the durability of the sprocket support and / or give the freedom to select the material of the sprocket support without reducing the durability of the sprocket support. Can be enhanced.

The schematic diagram of the drive train for a bicycle which concerns on embodiment. An exploded perspective view of the bicycle drive train shown in FIG. Sectional drawing of the bicycle drive train in line III-III of FIG. FIG. 2 is a perspective view of a bicycle rear hub assembly of a bicycle drive train shown in FIG. 2 having a lock member for a bicycle rear sprocket assembly. FIG. 1 is a side view of the bicycle rear sprocket assembly of the bicycle drive train shown in FIG. FIG. 4 is an enlarged cross-sectional view of the bicycle drive train shown in FIG. FIG. 5 is a side view of the sprocket of the bicycle rear sprocket assembly shown in FIG. FIG. 5 is a side view of the sprocket of the bicycle rear sprocket assembly shown in FIG. FIG. 5 is a side view of the sprocket of the bicycle rear sprocket assembly shown in FIG. FIG. 5 is a side view of the first sprocket of the bicycle rear sprocket assembly shown in FIG. FIG. 5 is a side view of the sprocket of the bicycle rear sprocket assembly shown in FIG. FIG. 5 is a side view of the sprocket of the bicycle rear sprocket assembly shown in FIG. FIG. 5 is a side view of the sprocket of the bicycle rear sprocket assembly shown in FIG. FIG. 5 is a side view of the sprocket of the bicycle rear sprocket assembly shown in FIG. FIG. 5 is a side view of the sprocket of the bicycle rear sprocket assembly shown in FIG. FIG. 5 is a side view of the sprocket of the bicycle rear sprocket assembly shown in FIG. FIG. 5 is a side view of the sprocket of the bicycle rear sprocket assembly shown in FIG. FIG. 5 is a side view of the sprocket of the bicycle rear sprocket assembly shown in FIG. An exploded perspective view of the rear sprocket assembly for a bicycle shown in FIG. FIG. 4 is a perspective view of a sprocket support of the bicycle rear hub assembly shown in FIG. Another perspective view of the sprocket support of the bicycle rear hub assembly shown in FIG. The rear view of the sprocket support of the bicycle rear hub assembly shown in FIG. FIG. 4 is a side view of the sprocket support of the bicycle rear hub assembly shown in FIG. A side view of a sprocket support of a bicycle rear hub assembly according to a modified example. FIG. 23 is an enlarged cross-sectional view of the sprocket support shown in FIG. FIG. 2 is a cross-sectional view of the sprocket support shown in FIG. FIG. 4 is a perspective view of the rear hub assembly for a bicycle shown in FIG. FIG. 4 is a side view of the bicycle rear hub assembly shown in FIG. The rear view of the bicycle rear hub assembly shown in FIG. An exploded perspective view of a sprocket support and a plurality of spacers of the bicycle rear hub assembly shown in FIG. FIG. 4 is an exploded enlarged cross-sectional view of the bicycle drive train shown in FIG. Another side view of the sprocket shown in FIG. FIG. 9 is a side view of the sprocket shown in FIG. FIG. 9 is a side view of the sprocket shown in FIG. 9 according to a modified example. An enlarged cross-sectional view of the sprocket shown in FIG. 29. Another cross-sectional view of the sprocket shown in FIG. 29. Another cross-sectional view of the bicycle drivetrain shown in FIG. An exploded perspective view of the sprocket shown in FIGS. 7 and 8. Other exploded perspective views of the sprocket shown in FIGS. 7 and 8. An exploded perspective view of a part of the bicycle rear hub assembly shown in FIG. An exploded perspective view of a part of the bicycle rear hub assembly shown in FIG. 40. An exploded perspective view of a part of the bicycle rear hub assembly shown in FIG. 40. An exploded perspective view of a part of the bicycle rear hub assembly shown in FIG. 40. FIG. 40 is a partial cross-sectional view of the bicycle rear hub assembly shown in FIG. FIG. 4 is a cross-sectional view of a bicycle rear hub assembly in line XLV-XLV of FIG. FIG. 40 is a perspective view of a spacer of the bicycle rear hub assembly shown in FIG. Another perspective view of the spacer of the bicycle rear hub assembly shown in FIG. 40. FIG. 4 is a schematic view showing the operation (pedaling) of the first ratchet member and the sprocket support of the bicycle rear hub assembly shown in FIG. 40. FIG. 4 is a schematic view showing the operation (inertia) of the first ratchet member and the sprocket support of the bicycle rear hub assembly shown in FIG. 40. An enlarged cross-sectional view of a sprocket support according to a modified example. An enlarged cross-sectional view of the sprocket according to the modified example. A side view of a sprocket support of a bicycle rear hub assembly according to a modified example. FIG. 52 is an enlarged cross-sectional view of the sprocket support shown in FIG. An exploded perspective view of the sprocket of the bicycle rear sprocket assembly according to the modified example. Another exploded perspective view of the sprocket of the bicycle rear sprocket assembly according to the modified example. A side view of the sprocket of the bicycle rear sprocket assembly according to the modified example. A side view of the sprocket of the bicycle rear sprocket assembly according to the modified example. A side view of the sprocket of the bicycle rear sprocket assembly according to the modified example. A side view of the sprocket shown in FIG. 57. FIG. 5 is an enlarged cross-sectional view of the sprocket shown in FIG. 57. The partial side view of the sprocket support member of the rear sprocket assembly for a bicycle which concerns on a modification. Sectional drawing of the drive train for a bicycle which concerns on a modification.

Here, an embodiment will be described with reference to the accompanying drawings. In various drawings, similar reference numerals indicate corresponding or identical elements.

As shown in FIG. 1, the bicycle drive train 10 according to the embodiment includes a bicycle rear hub assembly 12 and a bicycle rear sprocket assembly 14. The bicycle rear hub assembly 12 is fixed to the bicycle frame BF. The bicycle rear sprocket assembly 14 is attached to the bicycle rear hub assembly 12. The bicycle brake rotor 16 is attached to the bicycle rear hub assembly 12.

The bicycle drive train 10 further includes a crank assembly 18 and a bicycle chain 20. The crank assembly 18 includes a crankshaft 22, a right crank arm 24, a left crank arm 26, and a front sprocket 27. The right crank arm 24 and the left crank arm 26 are fixed to the crankshaft 22. The front sprocket 27 is fixed to at least one of the crankshaft 22 and the right crank arm 24. The bicycle chain 20 engages the front sprocket 27 and the bicycle rear sprocket assembly 14 so as to transmit pedaling force from the front sprocket 27 to the bicycle rear sprocket assembly 14. The crank assembly 18 includes a front sprocket 27 as a single sprocket in the illustrated embodiment. However, the crank assembly 18 may include a plurality of front sprockets. The bicycle rear sprocket assembly 14 is a rear sprocket assembly. However, the structure of the bicycle rear sprocket assembly 14 is applicable to the front sprocket.

In the present application, the terms "front", "rear", "front", "rear", "left", "right", "horizontal", "upward" and "downward" indicating the following directions. As well as any other similar orientation term refers to those orientations determined based on the user (eg, rider) by the bicycle saddle (not shown) facing the handlebars (not shown). Thus, as used to describe a bicycle drivetrain 10, a bicycle rear hub assembly 12, or a bicycle rear sprocket assembly 14, these terms are used in an upright riding position in a horizontal plane. Interpreted for a bicycle with a bicycle drivetrain 10, a bicycle rear hub assembly 12, or a bicycle rear sprocket assembly 14.

As shown in FIG. 2, the bicycle rear hub assembly 12 and the bicycle rear sprocket assembly 14 have a rotation center axis A1. The bicycle rear sprocket assembly 14 is rotatably supported by the bicycle rear hub assembly 12 with respect to the bicycle frame BF around the center of rotation A1 (FIG. 1). The bicycle rear sprocket assembly 14 is configured to engage the bicycle chain 20 so as to transmit a driving rotational force F1 between the bicycle chain 20 and the bicycle rear sprocket assembly 14 during pedaling. .. The bicycle rear sprocket assembly 14 rotates around the center of rotation A1 in the drive rotation direction D11 during pedaling. The drive rotation direction D11 is defined along the circumferential direction D1 of the bicycle rear hub assembly 12 or the bicycle rear sprocket assembly 14. The reverse rotation direction D12 is the opposite direction of the drive rotation direction D11, and is defined along the circumferential direction D1.

As shown in FIG. 2, the bicycle rear hub assembly 12 includes a sprocket support 28. The bicycle rear sprocket assembly 14 is configured to be attached to the sprocket support 28 of the bicycle rear hub assembly 12. The bicycle rear sprocket assembly 14 is attached to the sprocket support 28 so as to transmit a driving rotational force F1 between the bicycle rear sprocket assembly 28 and the bicycle rear sprocket assembly 14. The bicycle rear hub assembly 12 has a hub axle 30. The sprocket support 28 is rotatably attached to the hub axle 30 around the center of rotation A1. The bicycle rear sprocket assembly 14 further includes a locking member 32. The lock member 32 is fixed to the sprocket support 28 so as to hold the bicycle rear sprocket assembly 14 with respect to the sprocket support 28 in the axial direction D2 with respect to the rotation center axis A1.

As shown in FIG. 3, the bicycle rear hub assembly 12 is fixed to the bicycle frame BF by the wheel fixing mechanism WS. The hub axle 30 includes an axle through hole 30A. The fixing rod WS1 of the wheel fixing mechanism WS extends through the axle through hole 30A of the hub axle 30. The hub axle 30 includes a first axle end 30B and a second axle end 30C. The hub axle 30 extends between the first axle end 30B and the second axle end 30C along the center of rotation A1. The first axle end 30B is provided in the first recess BF11 of the first frame BF1 of the bicycle frame BF. The second axle end 30C is provided in the second recess BF21 of the second frame BF2 of the bicycle frame BF. The hub axle 30 is held between the first frame BF1 and the second frame BF2 by the wheel fixing mechanism WS. The wheel fixing mechanism WS includes a structure known in the bicycle field. Therefore, for the sake of brevity, detailed description thereof will be omitted here.

In the present embodiment, the axle through hole 30A has a minimum inner diameter BD1 of 13 mm or more. The minimum inner diameter BD1 of the axle through hole 30A is preferably 14 mm or more. The minimum inner diameter BD1 of the axle through hole 30A is preferably 21 mm or less. In the present embodiment, the minimum inner diameter BD1 of the axle through hole 30A is 15 mm. However, the minimum inner diameter BD1 is not limited to this embodiment and the above range.

The hub axle 30 has a maximum outer diameter BD2 of 17 mm or more. The maximum outer diameter BD2 of the hub axle 30 is preferably 20 mm or more. The maximum outer diameter BD2 of the hub axle 30 is preferably 23 mm or less. In the present embodiment, the maximum outer diameter BD2 of the hub axle 30 is 21 mm. However, the maximum outer diameter BD2 of the hub axle 30 is not limited to this embodiment and the above range. The hub axle 30 has a minimum outer diameter BD3 of 15 mm or more. The minimum outer diameter BD3 is preferably 17 mm or more. The minimum outer diameter BD3 is preferably 19 mm or less. In the present embodiment, the minimum outer diameter BD3 of the hub axle 30 is 17.6 mm. However, the minimum outer diameter BD3 is not limited to this embodiment and the above range.

The hub axle 30 includes an axle tube 30X, a first axle portion 30Y, and a second axle portion 30Z. The axle tube 30X has a tubular shape and extends along the rotation center axis A1. The first axle portion 30Y is fixed to the first end portion of the axle tube 30X. The second axle portion 30Z is fixed to the second end portion of the axle tube 30X. At least one of the first axle portion 30Y and the second axle portion 30Z may be provided integrally with the axle tube 30X.

As shown in FIGS. 3 and 4, the bicycle rear hub assembly 12 further includes a brake rotor support 34. The brake rotor support 34 is rotatably attached to the hub axle 30 around the center of rotation A1. The brake rotor support 34 is connected to the bicycle brake rotor 16 (FIG. 1) so as to transmit the braking rotational force from the bicycle brake rotor 16 to the brake rotor support 34.

As shown in FIG. 4, the bicycle rear hub assembly 12 includes a hub body 36. The hub body 36 is rotatably attached to the hub axle 30 around the rotation center axis A1 of the bicycle rear hub assembly 12. In the present embodiment, the sprocket support 28 is a member separate from the hub body 36. The brake rotor support 34 is provided integrally with the hub body 36 as one single member. However, the sprocket support 28 may be provided integrally with the hub body 36. The brake rotor support 34 may be a member separate from the hub body 36. For example, the hub body 36 is made of a metal material containing aluminum.

As shown in FIG. 5, the bicycle rear sprocket assembly 14 includes a plurality of bicycle sprockets. The plurality of bicycle sprockets have a first sprocket and a second sprocket. In the present embodiment, the plurality of bicycle sprockets have a plurality of first sprockets SP1 and SP2 provided as the first sprockets. Further, the plurality of bicycle sprockets have a plurality of second sprockets SP3 and SP4 provided as the second sprockets. Multiple bicycle sprockets have additional sprockets. In this embodiment, the plurality of bicycle sprockets has a plurality of additional sprockets SP5 to SP12. However, the total number of first sprockets is not limited to this embodiment. The total number of second sprockets is not limited to this embodiment. The total number of additional sprockets is not limited to this embodiment. Further, in the present embodiment, the first sprocket SP1 is a sprocket separate from the first sprocket SP2, but the first sprocket SP1 and SP2 may be integrally formed as one single member. Similarly, in the present embodiment, the second sprocket SP3 is a sprocket separate from the second sprocket SP4, but the second sprocket SP3 and SP4 may be integrally formed as one single member.

For example, the total number of a plurality of bicycle sprockets is 10 or more. The total number of plurality of bicycle sprockets may be 11 or more. The total number of plurality of bicycle sprockets may be 12 or more. In this embodiment, the total number of the plurality of bicycle sprockets is 12. However, the total number of a plurality of bicycle sprockets is not limited to this embodiment. For example, the total number of plurality of bicycle sprockets may be 13, 14, or 15 or more.

In this embodiment, the first sprocket SP1 is the smallest sprocket in the bicycle rear sprocket assembly 14. The additional sprocket SP12 is the largest sprocket in the bicycle rear sprocket assembly 14. The first sprocket SP2 corresponds to the top gear in the bicycle rear sprocket assembly 14. The additional sprocket SP12 corresponds to the low gear in the bicycle rear sprocket assembly 14.

As shown in FIG. 5, the first sprocket SP1 has a pitch circle diameter PCD1. The first sprocket SP2 has a pitch circle diameter PCD2. The second sprocket SP3 has a pitch circle diameter PCD3. The second sprocket SP4 has a pitch circle diameter PCD4. The additional sprocket SP5 has a pitch circle diameter PCD5. The additional sprocket SP6 has a pitch circle diameter PCD6. The additional sprocket SP7 has a pitch circle diameter PCD7. The additional sprocket SP8 has a pitch circle diameter PCD8. The additional sprocket SP9 has a pitch circle diameter PCD9. The additional sprocket SP10 has a pitch circle diameter PCD10. The additional sprocket SP11 has a pitch circle diameter PCD11. The additional sprocket SP12 has a pitch circle diameter PCD12.

The first sprocket SP1 has a pitch circle PC1 having a pitch circle diameter PCD1. The first sprocket SP2 has a pitch circle PC2 having a pitch circle diameter PCD2. The second sprocket SP3 has a pitch circle PC3 with a pitch circle diameter PCD3. The second sprocket SP4 has a pitch circle PC4 having a pitch circle diameter PCD4. The additional sprocket SP5 has a pitch circle PC5 with a pitch circle diameter PCD5. The additional sprocket SP6 has a pitch circle PC6 with a pitch circle diameter PCD6. The additional sprocket SP7 has a pitch circle PC7 with a pitch circle diameter PCD7. The additional sprocket SP8 has a pitch circle PC8 with a pitch circle diameter PCD8. The additional sprocket SP9 has a pitch circle PC9 with a pitch circle diameter PCD9. The additional sprocket SP10 has a pitch circle PC10 with a pitch circle diameter PCD10. The additional sprocket SP11 has a pitch circle PC11 with a pitch circle diameter PCD11. The additional sprocket SP12 has a pitch circle PC12 with a pitch circle diameter PCD12.

The pitch circle PC1 of the first sprocket SP1 is defined by the central axis of the pin of the bicycle chain 20 (FIG. 2) that is engaged with the first sprocket SP1. The pitch circles PC2 to PC12 are defined in the same manner as the pitch circle PC1. Therefore, for the sake of brevity, detailed description thereof will be omitted here.

In this embodiment, the pitch circle diameter PCD1 is smaller than the pitch circle diameter PCD2. The pitch circle diameter PCD2 is smaller than the pitch circle diameter PCD3. The pitch circle diameter PCD3 is smaller than the pitch circle diameter PCD4. The pitch circle diameter PCD4 is smaller than the pitch circle diameter PCD5. The pitch circle diameter PCD5 is smaller than the pitch circle diameter PCD6. The pitch circle diameter PCD6 is smaller than the pitch circle diameter PCD7. The pitch circle diameter PCD7 is smaller than the pitch circle diameter PCD8. The pitch circle diameter PCD8 is smaller than the pitch circle diameter PCD9. The pitch circle diameter PCD9 is smaller than the pitch circle diameter PCD10. The pitch circle diameter PCD10 is smaller than the pitch circle diameter PCD11. The pitch circle diameter PCD 11 is smaller than the pitch circle diameter PCD 12.

The pitch circle diameter PCD1 is the minimum pitch circle diameter in the bicycle rear sprocket assembly 14. The pitch circle diameter PCD 12 is the maximum pitch circle diameter in the bicycle rear sprocket assembly 14. The first sprocket SP1 corresponds to the top gear in the bicycle rear sprocket assembly 14. The additional sprocket SP12 corresponds to the low gear in the bicycle rear sprocket assembly 14. However, the first sprocket SP1 may correspond to other gears in the bicycle rear sprocket assembly 14. The additional sprocket SP12 may correspond to other gears in the bicycle rear sprocket assembly 14.

As shown in FIG. 6, the first sprocket SP2 is the first sprocket SP2 without having another sprocket between the first sprocket SP1 and SP2 in the axial direction D2 with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. Adjacent to the sprocket SP1. The second sprocket SP3 is adjacent to the first sprocket SP2 without having another sprocket between the first sprocket SP2 and the second sprocket SP3 in the axial direction D2 with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. is doing. The second sprocket SP4 is adjacent to the second sprocket SP3 without having another sprocket between the second sprocket SP3 and the second sprocket SP4 in the axial direction D2 with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. is doing. The first sprockets SP1 and SP2, the second sprockets SP3, the second sprockets SP4, and the additional sprockets SP5 to SP12 are arranged side by side in the axial direction D2 in this order.

As shown in FIG. 7, the first sprocket SP1 includes a sprocket body SP1A and a plurality of sprocket teeth SP1B. The plurality of sprocket teeth SP1B extend radially outward from the sprocket body SP1A with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. The total number of teeth of the first sprocket SP1 (total number of at least one sprocket tooth SP1B) is 10 or less. In the present embodiment, the total number of at least one sprocket tooth SP1B of the first sprocket SP1 is 10. However, the total number of the plurality of sprocket teeth SP1B of the first sprocket SP1 is not limited to the present embodiment and the above range.

As shown in FIG. 8, the first sprocket SP2 includes a sprocket body SP2A and a plurality of sprocket teeth SP2B. The plurality of sprocket teeth SP2B extend radially outward from the sprocket body SP2A with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. In this embodiment, the total number of at least one sprocket tooth SP2B is twelve. However, the total number of the plurality of sprocket teeth SP2B of the first sprocket SP2 is not limited to this embodiment.

The first sprocket SP2 includes at least one first shift promotion region SP2F1 for promoting the first shift operation in which the bicycle chain 20 shifts from the first sprocket SP2 to the first sprocket SP1. The first sprocket SP2 includes at least one second shift promotion region SP2F2 for promoting the second shift operation in which the bicycle chain 20 shifts from the first sprocket SP1 to the first sprocket SP2. In the present embodiment, the first sprocket SP2 includes a plurality of first shift promotion regions SP2F1 for promoting the first shift operation. The first sprocket SP2 includes a plurality of second shift promotion regions SP2F2 for promoting the second shift operation. However, the total number of the first shift promotion region SP2F1 is not limited to this embodiment. The total number of the second shift promotion region SP2F2 is not limited to this embodiment. As used herein, the term "shift facilitation region" is intentionally designed to facilitate the shifting motion of a bicycle chain from one sprocket to another axially adjacent sprocket within that region. Intended area.

In the present embodiment, the first sprocket SP2 includes a plurality of first shift promotion recesses SP2R1 for promoting the first shift operation. The first sprocket SP2 includes a plurality of second shift promotion recesses SP2R2 for promoting the second shift operation. The first shift promotion recess SP2R1 is provided in the first shift promotion region SP2F1. However, the first shift promotion region SP2F1 may include other structures in place of or in addition to the first shift promotion recess SP2R1. The second shift promotion region SP2F2 may include other structures in place of or in addition to the second shift promotion recess SP2R2.

As shown in FIG. 9, the second sprocket SP3 includes a sprocket body SP3A and a plurality of sprocket teeth SP3B. The plurality of sprocket teeth SP3B extend radially outward from the sprocket body SP3A with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. In this embodiment, the total number of at least one sprocket tooth SP3B is 14. However, the total number of the plurality of sprocket teeth SP3B of the second sprocket SP3 is not limited to this embodiment.

The second sprocket SP3 includes at least one first shift promotion region SP3F1 for the bicycle chain 20 to promote the first shift operation from the second sprocket SP3 to the first sprocket SP2 (FIG. 6). The second sprocket SP3 includes at least one second shift promotion region SP3F2 for the bicycle chain 20 to promote the second shift operation from the first sprocket SP2 (FIG. 6) to the second sprocket SP3. In the present embodiment, the second sprocket SP3 includes a plurality of first shift promotion regions SP3F1 for promoting the first shift operation. The second sprocket SP3 includes a plurality of second shift promotion regions SP3F2 for promoting the second shift operation. However, the total number of the first shift promotion region SP3F1 is not limited to this embodiment. The total number of the second shift promotion region SP3F2 is not limited to this embodiment.

In the present embodiment, the second sprocket SP3 includes a plurality of first shift promotion recesses SP3R1 for promoting the first shift operation. The second sprocket SP3 includes a plurality of second shift promotion recesses SP3R2 for promoting the second shift operation. The first shift promotion recess SP3R1 is provided in the first shift promotion region SP3F1. However, the first shift promotion region SP3F1 may include other structures in place of or in addition to the first shift promotion recess SP3R1. The second shift promotion region SP3F2 may include other structures in place of or in addition to the second shift promotion recess SP3R2.

As shown in FIG. 10, the second sprocket SP4 includes a sprocket body SP4A and a plurality of sprocket teeth SP4B. The plurality of sprocket teeth SP4B extend radially outward from the sprocket body SP4A with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. In this embodiment, the total number of at least one sprocket tooth SP4B is 16. However, the total number of the plurality of sprocket teeth SP4B of the second sprocket SP4 is not limited to this embodiment.

The second sprocket SP4 includes at least one first shift promotion region SP4F1 for the bicycle chain 20 to promote the first shift operation from the second sprocket SP4 to the second sprocket SP3. The second sprocket SP4 includes at least one second shift promotion region SP4F2 for the bicycle chain 20 to promote the second shift operation from the second sprocket SP3 to the second sprocket SP4. In the present embodiment, the second sprocket SP4 includes a plurality of first shift promotion regions SP4F1 for promoting the first shift operation. The second sprocket SP4 includes a plurality of second shift promotion regions SP4F2 for promoting the second shift operation. However, the total number of the first shift promotion region SP4F1 is not limited to this embodiment. The total number of the second shift promotion region SP4F2 is not limited to this embodiment.

In the present embodiment, the second sprocket SP4 includes a plurality of first shift promotion recesses SP4R1 for promoting the first shift operation. The second sprocket SP4 includes a plurality of second shift promotion recesses SP4R2 for promoting the second shift operation. The first shift promotion recess SP4R1 is provided in the first shift promotion region SP4F1. However, the first shift promotion region SP4F1 may include other structures in place of or in addition to the first shift promotion recess SP4R1. The second shift promotion region SP4F2 may include other structures in place of or in addition to the second shift promotion recess SP4R2.

As shown in FIG. 11, the additional sprocket SP5 includes a sprocket body SP5A and a plurality of sprocket teeth SP5B. The plurality of sprocket teeth SP5B extend radially outward from the sprocket body SP5A with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. In this embodiment, the total number of at least one sprocket tooth SP5B is 18. However, the total number of the plurality of sprocket teeth SP5B of the additional sprocket SP5 is not limited to this embodiment.

The additional sprocket SP5 includes at least one first shift promotion region SP5F1 for facilitating the first shift operation in which the bicycle chain 20 shifts from the additional sprocket SP5 to the adjacent small sprocket SP4. The additional sprocket SP5 includes at least one second shift promotion region SP5F2 for facilitating a second shift operation in which the bicycle chain 20 shifts from the adjacent small sprocket SP4 to the additional sprocket SP5. The adjacent small sprocket SP4 is adjacent to the additional sprocket SP5 without having another sprocket between the additional sprocket SP5 and the adjacent small sprocket SP4 in the axial direction D2 with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. In the present embodiment, the additional sprocket SP5 includes a plurality of first shift promotion regions SP5F1 for promoting the first shift operation. The additional sprocket SP5 includes a plurality of second shift promotion regions SP5F2 for promoting the second shift operation. However, the total number of the first shift promotion region SP5F1 is not limited to this embodiment. The total number of the second shift promotion region SP5F2 is not limited to this embodiment.

In the present embodiment, the additional sprocket SP5 includes a plurality of first shift promotion recesses SP5R1 for promoting the first shift operation. The additional sprocket SP5 includes a plurality of second shift promotion recesses SP5R2 for promoting the second shift operation. The first shift promotion recess SP5R1 is provided in the first shift promotion region SP5F1. The second shift promotion recess SP5R2 is provided in the second shift promotion region SP5F2. However, the first shift promotion region SP5F1 may include other structures in place of or in addition to the first shift promotion recess SP5R1. The second shift promotion region SP5F2 may include other structures in place of or in addition to the second shift promotion recess SP5R2.

As shown in FIG. 12, the additional sprocket SP6 includes a sprocket body SP6A and a plurality of sprocket teeth SP6B. The plurality of sprocket teeth SP6B extend radially outward from the sprocket body SP6A with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. In this embodiment, the total number of at least one sprocket tooth SP6B is 21. However, the total number of the plurality of sprocket teeth SP6B of the additional sprocket SP6 is not limited to this embodiment.

The additional sprocket SP6 includes at least one first shift promotion region SP6F1 for facilitating the first shift operation in which the bicycle chain 20 shifts from the additional sprocket SP6 to the adjacent small sprocket SP5. The additional sprocket SP6 includes at least one second shift promotion region SP6F2 for facilitating a second shift operation in which the bicycle chain 20 shifts from the adjacent small sprocket SP5 to the additional sprocket SP6. The adjacent small sprocket SP5 is adjacent to the additional sprocket SP6 without having another sprocket between the additional sprocket SP6 and the adjacent small sprocket SP5 in the axial direction D2 with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. There is. In the present embodiment, the additional sprocket SP6 includes a plurality of first shift promotion regions SP6F1 for promoting the first shift operation. The additional sprocket SP6 includes a plurality of second shift promotion regions SP6F2 for promoting the second shift operation. However, the total number of the first shift promotion region SP6F1 is not limited to this embodiment. The total number of the second shift promotion region SP6F2 is not limited to this embodiment.

In the present embodiment, the additional sprocket SP6 includes a plurality of first shift promotion recesses SP6R1 for promoting the first shift operation. The additional sprocket SP6 includes a plurality of second shift promotion recesses SP6R2 for facilitating the second shift operation. The first shift promotion recess SP6R1 is provided in the first shift promotion region SP6F1. The second shift promotion recess SP6R2 is provided in the second shift promotion region SP6F2. However, the first shift promotion region SP6F1 may include other structures in place of or in addition to the first shift promotion recess SP6R1. The second shift promotion region SP6F2 may include other structures in place of or in addition to the second shift promotion recess SP6R2.

As shown in FIG. 13, the additional sprocket SP7 includes a sprocket body SP7A and a plurality of sprocket teeth SP7B. The plurality of sprocket teeth SP7B extend radially outward from the sprocket body SP7A with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. In this embodiment, the total number of at least one sprocket tooth SP7B is 24. However, the total number of the plurality of sprocket teeth SP7B of the additional sprocket SP7 is not limited to this embodiment.

The additional sprocket SP7 includes at least one first shift promotion region SP7F1 for facilitating the first shift operation in which the bicycle chain 20 shifts from the additional sprocket SP7 to the adjacent small sprocket SP6. The additional sprocket SP7 includes at least one second shift promotion region SP7F2 for facilitating a second shift operation in which the bicycle chain 20 shifts from the adjacent small sprocket SP6 to the additional sprocket SP7. The adjacent small sprocket SP6 is adjacent to the additional sprocket SP7 without having another sprocket between the additional sprocket SP7 and the adjacent small sprocket SP6 in the axial direction D2 with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. There is. In the present embodiment, the additional sprocket SP7 includes a plurality of first shift promotion regions SP7F1 for promoting the first shift operation. The additional sprocket SP7 includes a plurality of second shift promotion regions SP7F2 for promoting the second shift operation. However, the total number of the first shift promotion region SP7F1 is not limited to this embodiment. The total number of the second shift promotion region SP7F2 is not limited to this embodiment.

In the present embodiment, the additional sprocket SP7 includes a plurality of first shift promotion recesses SP7R1 for promoting the first shift operation. The additional sprocket SP7 includes a plurality of second shift promotion recesses SP7R2 for promoting the second shift operation. The first shift promotion recess SP7R1 is provided in the first shift promotion region SP7F1. The second shift promotion recess SP7R2 is provided in the second shift promotion region SP7F2. However, the first shift promotion region SP7F1 may include other structures in place of or in addition to the first shift promotion recess SP7R1. The second shift promotion region SP7F2 may include other structures in place of or in addition to the second shift promotion recess SP7R2.

As shown in FIG. 14, the additional sprocket SP8 includes a sprocket body SP8A and a plurality of sprocket teeth SP8B. The plurality of sprocket teeth SP8B extend radially outward from the sprocket body SP8A with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. In this embodiment, the total number of at least one sprocket tooth SP8B is 28. However, the total number of the plurality of sprocket teeth SP8B of the additional sprocket SP8 is not limited to this embodiment.

The additional sprocket SP8 includes at least one first shift promotion region SP8F1 for facilitating the first shift operation in which the bicycle chain 20 shifts from the additional sprocket SP8 to the adjacent small sprocket SP7. The additional sprocket SP8 includes at least one second shift promotion region SP8F2 for facilitating a second shift operation in which the bicycle chain 20 shifts from the adjacent small sprocket SP7 to the additional sprocket SP8. The adjacent small sprocket SP7 is adjacent to the additional sprocket SP8 without having another sprocket between the additional sprocket SP8 and the adjacent small sprocket SP7 in the axial direction D2 with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. There is. In the present embodiment, the additional sprocket SP8 includes a plurality of first shift promotion regions SP8F1 for promoting the first shift operation. The additional sprocket SP8 includes a plurality of second shift promotion regions SP8F2 for promoting the second shift operation. However, the total number of the first shift promotion region SP8F1 is not limited to this embodiment. The total number of the second shift promotion region SP8F2 is not limited to this embodiment.

In the present embodiment, the additional sprocket SP8 includes a plurality of first shift promotion recesses SP8R1 for promoting the first shift operation. The additional sprocket SP8 includes a plurality of second shift promoting recesses SP8R2 for facilitating the second shift operation. The first shift promotion recess SP8R1 is provided in the first shift promotion region SP8F1. The second shift promotion recess SP8R2 is provided in the second shift promotion region SP8F2. However, the first shift promotion region SP8F1 may include other structures in place of or in addition to the first shift promotion recess SP8R1. The second shift promotion region SP8F2 may include other structures in place of or in addition to the second shift promotion recess SP8R2.

As shown in FIG. 15, the additional sprocket SP9 includes a sprocket body SP9A and a plurality of sprocket teeth SP9B. The plurality of sprocket teeth SP9B extend radially outward from the sprocket body SP9A with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. In this embodiment, the total number of at least one sprocket tooth SP9B is 33. However, the total number of the plurality of sprocket teeth SP9B of the additional sprocket SP9 is not limited to this embodiment.

The additional sprocket SP9 includes at least one first shift promotion region SP9F1 for facilitating the first shift operation in which the bicycle chain 20 shifts from the additional sprocket SP9 to the adjacent small sprocket SP8. The additional sprocket SP9 includes at least one second shift promotion region SP9F2 for facilitating a second shift operation in which the bicycle chain 20 shifts from the adjacent small sprocket SP8 to the additional sprocket SP9. The adjacent small sprocket SP8 is adjacent to the additional sprocket SP9 without having another sprocket between the additional sprocket SP9 and the adjacent small sprocket SP8 in the axial direction D2 with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. There is. In the present embodiment, the additional sprocket SP9 includes a plurality of first shift promotion regions SP9F1 for promoting the first shift operation. The additional sprocket SP9 includes a plurality of second shift promotion regions SP9F2 for promoting the second shift operation. However, the total number of the first shift promotion region SP9F1 is not limited to this embodiment. The total number of the second shift promotion region SP9F2 is not limited to this embodiment.

In the present embodiment, the additional sprocket SP9 includes a plurality of first shift promotion recesses SP9R1 for promoting the first shift operation. The additional sprocket SP9 includes a plurality of second shift promotion recesses SP9R2 for promoting the second shift operation. The first shift promotion recess SP9R1 is provided in the first shift promotion region SP9F1. The second shift promotion recess SP9R2 is provided in the second shift promotion region SP9F2. However, the first shift promotion region SP9F1 may include other structures in place of or in addition to the first shift promotion recess SP9R1. The second shift promotion region SP9F2 may include other structures in place of or in addition to the second shift promotion recess SP9R2.

As shown in FIG. 16, the additional sprocket SP10 includes a sprocket body SP10A and a plurality of sprocket teeth SP10B. The plurality of sprocket teeth SP10B extend radially outward from the sprocket body SP10A with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. In this embodiment, the total number of at least one sprocket tooth SP10B is 39. However, the total number of the plurality of sprocket teeth SP10B of the additional sprocket SP10 is not limited to this embodiment.

The additional sprocket SP10 includes at least one first shift promotion region SP10F1 for facilitating the first shift operation in which the bicycle chain 20 shifts from the additional sprocket SP10 to the adjacent small sprocket SP9. The additional sprocket SP10 includes at least one second shift promotion region SP10F2 for the bicycle chain 20 to facilitate the second shift operation from the adjacent small sprocket SP9 to the additional sprocket SP10. The adjacent small sprocket SP9 is adjacent to the additional sprocket SP10 without having another sprocket between the additional sprocket SP10 and the adjacent small sprocket SP9 in the axial direction D2 with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. There is. In the present embodiment, the additional sprocket SP10 includes a plurality of first shift promotion regions SP10F1 for promoting the first shift operation. The additional sprocket SP10 includes a second shift promotion region SP10F2 for promoting the second shift operation. However, the total number of the first shift promotion region SP10F1 is not limited to this embodiment. The total number of the second shift promotion region SP10F2 is not limited to this embodiment.

In the present embodiment, the additional sprocket SP10 includes a plurality of first shift promotion recesses SP10R1 for promoting the first shift operation. The additional sprocket SP10 includes a plurality of second shift promotion recesses SP10R2 for promoting the second shift operation. The first shift promotion recess SP10R1 is provided in the first shift promotion region SP10F1. The second shift promotion recess SP10R2 is provided in the second shift promotion region SP10F2. However, the first shift promotion region SP10F1 may include other structures in place of or in addition to the first shift promotion recess SP10R1. The second shift promotion region SP10F2 may include other structures in place of or in addition to the second shift promotion recess SP10R2.

As shown in FIG. 17, the additional sprocket SP11 includes a sprocket body SP11A and a plurality of sprocket teeth SP11B. The plurality of sprocket teeth SP11B extend radially outward from the sprocket body SP11A with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. In this embodiment, the total number of at least one sprocket tooth SP11B is 45. However, the total number of the plurality of sprocket teeth SP11B of the additional sprocket SP11 is not limited to this embodiment.

The additional sprocket SP11 includes at least one first shift promotion region SP11F1 for facilitating the first shift operation in which the bicycle chain 20 shifts from the additional sprocket SP11 to the adjacent small sprocket SP10. The additional sprocket SP11 includes at least one second shift promotion region SP11F2 for facilitating a second shift operation in which the bicycle chain 20 shifts from the adjacent small sprocket SP10 to the additional sprocket SP11. The adjacent small sprocket SP10 is adjacent to the additional sprocket SP11 without having another sprocket between the additional sprocket SP11 and the adjacent small sprocket SP10 in the axial direction D2 with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. There is. In the present embodiment, the additional sprocket SP11 includes a plurality of first shift promotion regions SP11F1 for promoting the first shift operation. The additional sprocket SP11 includes a plurality of second shift promotion regions SP11F2 for promoting the second shift operation. However, the total number of the first shift promotion region SP11F1 is not limited to this embodiment. The total number of the second shift promotion region SP11F2 is not limited to this embodiment.

In the present embodiment, the additional sprocket SP11 includes a plurality of first shift promotion recesses SP11R1 for promoting the first shift operation. The additional sprocket SP11 includes a plurality of second shift promotion recesses SP11R2 for promoting the second shift operation. The first shift promotion recess SP11R1 is provided in the first shift promotion region SP11F1. The second shift promotion recess SP11R2 is provided in the second shift promotion region SP11F2. However, the first shift promotion region SP11F1 may include other structures in place of or in addition to the first shift promotion recess SP11R1. The second shift promotion region SP11F2 may include other structures in place of or in addition to the second shift promotion recess SP11R2.

As shown in FIG. 18, the additional sprocket SP12 includes a sprocket body SP12A and a plurality of sprocket teeth SP12B. The plurality of sprocket teeth SP12B extend radially outward from the sprocket body SP12A with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. The total number of teeth of the additional sprocket SP12 is 46 or more. The total number of teeth of the additional sprocket SP12 may be 50 or more. In this embodiment, the total number of teeth of the additional sprocket SP12 is 51. However, the total number of at least one sprocket tooth SP12B of the additional sprocket SP12 is not limited to this embodiment and the above range.

The additional sprocket SP12 includes at least one first shift promotion region SP12F1 for facilitating the first shift operation in which the bicycle chain 20 shifts from the additional sprocket SP12 to the adjacent small sprocket SP11. The additional sprocket SP12 includes at least one second shift promotion region SP12F2 for facilitating a second shift operation in which the bicycle chain 20 shifts from the adjacent small sprocket SP11 to the additional sprocket SP12. The adjacent small sprocket SP11 is adjacent to the additional sprocket SP12 without having another sprocket between the additional sprocket SP12 and the adjacent small sprocket SP11 in the axial direction D2 with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. There is. In the present embodiment, the additional sprocket SP12 includes a plurality of first shift promotion regions SP12F1 for promoting the first shift operation. The additional sprocket SP12 includes a second shift promotion region SP12F2 for promoting the second shift operation. However, the total number of the first shift promotion region SP12F1 is not limited to this embodiment. The total number of the second shift promotion region SP12F2 is not limited to this embodiment.

In the present embodiment, the additional sprocket SP12 includes a plurality of first shift promotion recesses SP12R1 for promoting the first shift operation. The additional sprocket SP12 includes a plurality of second shift promotion recesses SP12R2 for facilitating the second shift operation. The first shift promotion recess SP12R1 is provided in the first shift promotion region SP12F1. The second shift promotion recess SP12R2 is provided in the second shift promotion region SP12F2. However, the first shift promotion region SP12F1 may include other structures in place of or in addition to the first shift promotion recess SP12R1. The second shift promotion region SP12F2 may include other structures in place of or in addition to the second shift promotion recess SP12R2.

As shown in FIG. 19, the sprockets SP1 to SP12 are separate members from each other. However, at least one of the sprockets SP1 to SP12 may be provided at least partially integrally with the other sprockets of the sprockets SP1 to SP12. All of the sprockets SP1 to SP12 may be integrally formed with each other as one single unit. In such cases, at least one of the sprockets SP3 to SP12 may include at least 10 inner spline teeth.

The bicycle rear sprocket assembly 14 further includes a sprocket support member 37, a plurality of spacers 38, a first ring 39A, and a second ring 39B. The first ring 39A is provided between the second sprocket SP3 and the second sprocket SP4 in the axial direction D2. The second ring 39B is provided between the second sprocket SP4 and the additional sprocket SP5 in the axial direction D2. The additional sprocket is configured to be attached to the sprocket support member 37. In this embodiment, the additional sprockets SP5 to SP12 are configured to be attached to the sprocket support member 37.

As shown in FIG. 6, for example, the additional sprocket is attached to the sprocket support member 37 by the adhesive 37A. In this embodiment, the additional sprockets SP5 to SP12 are attached to the sprocket support member 37 by the adhesive 37A. Therefore, the weight of the bicycle rear sprocket assembly 14 can be reduced by reducing the number of metal fixtures or eliminating the metal fixtures. However, at least one of the additional sprockets SP5 to SP12 may be attached to the sprocket support member 37 by a structure other than the adhesive 37A (including a metal fixture). At least one of the additional sprockets SP5 to SP12 may be engaged with the sprocket support 28 without having the sprocket support member 37. The sprocket support member 37 can be omitted from the bicycle rear sprocket assembly 14. Further, at least one of the second sprockets SP3 and SP4 may be attached to the sprocket support member 37.

As shown in FIG. 4, the lock member 32 includes a tubular portion 32A, a male screw portion 32B, and a radial protrusion 32C. The tubular portion 32A includes a first axial end 32D and a second axial end 32E. The second axial end 32E is arranged on the opposite side of the first axial end 32D in the axial direction D2 with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. As shown in FIG. 6, the first axial end 32D is a bicycle rear hub assembly rather than the second axial end 32E in a state where the bicycle rear sprocket assembly 14 is mounted on the bicycle rear hub assembly 12. It is arranged at a position close to the axial center plane CPL of the twelve. The axial center plane CPL is perpendicular to the rotation center axis A1. As shown in FIG. 3, the axial center plane CPL is defined to bisect the axial length of the bicycle rear hub assembly 12 in the axial direction D2.

As shown in FIG. 6, the male screw portion 32B has a female screw portion 28A of the sprocket support 28 of the bicycle rear hub assembly 12 in a state where the bicycle rear sprocket assembly 14 is mounted on the bicycle rear hub assembly 12. It is provided on the first axial end 32D so as to engage. The radial protrusion 32C limits the axial movement of the first sprocket SP2 with respect to the sprocket support 28 of the bicycle rear hub assembly 12 with the bicycle rear sprocket assembly 14 mounted on the bicycle rear hub assembly 12. Extends radially outward with respect to the center of rotation A1 from the second axial end 32E.

The first sprocket SP1 includes a first inner side surface SP1G and a first outer side surface SP1H. The first outer side surface SP1H is arranged on the side opposite to the first inner side surface SP1G in the axial direction D2. The radial protrusion 32C is configured to come into contact with the first sprocket SP1 on the first outer side surface SP1H. The first sprocket SP1 and SP2 are arranged between the radial protrusion 32C and the second sprocket SP3 in the axial direction. The first sprocket SP1 and SP2, the second sprocket SP3, the second sprocket SP4, and the first ring 39A are held between the radial protrusion 32C and the sprocket support member 37 in the axial direction D2.

As shown in FIG. 4, the lock member 32 has a tool engaging portion 32F. The tool engaging portion 32F is provided on the inner peripheral surface 32A1 of the tubular portion 32A so as to be engaged with a fixture (not shown). In the present embodiment, the tool engaging portion 32F has a plurality of engagements such that the lock member 32 is engaged with the fixture when the lock member 32 is screwed onto the sprocket support 28 by the male screw portion 32B and the female screw portion 28A. Includes groove 32G.

As shown in FIGS. 20 and 21, the sprocket support 28 includes at least one outer spline tooth 40 configured to engage the bicycle rear sprocket assembly 14 (FIG. 6). The sprocket support 28 includes at least 10 outer spline teeth 40 configured to engage the bicycle rear sprocket assembly 14 (FIG. 6). That is, at least one outer spline tooth 40 includes a plurality of outer spline teeth 40.

The sprocket support 28 includes a base support 41 having a tubular shape. The base support portion 41 extends along the rotation center axis A1. The outer spline teeth 40 extend radially outward from the base support 41. The sprocket support 28 includes a large diameter portion 42, a flange 44, and a plurality of outer helical spline teeth 46. The large diameter portion 42 and the flange 44 extend radially outward from the base support portion 41. The large diameter portion 42 is provided between the plurality of outer spline teeth 40 and the flange 44 in the axial direction D2. The large diameter portion 42 and the flange are provided between the plurality of outer spline teeth 40 and the plurality of outer helical spline teeth 46 in the axial direction D2. As shown in FIG. 6, the bicycle rear sprocket assembly 14 is held between the large diameter portion 42 and the radial protrusion 32C of the lock member 32 in the axial direction D2. The large diameter portion 42 may have an internal cavity so that a drive mechanism such as a one-way clutch mechanism can be accommodated in the internal cavity. The large diameter portion 42 can be omitted from the bicycle rear hub assembly 12 if necessary.

As shown in FIG. 22, at least one of the at least 10 outer spline teeth 40 has a spline tooth axial length SL1. Each of the plurality of outer spline teeth 40 has a spline tooth axial length SL1. The spline tooth axial length SL1 is 27 mm or less. The spline tooth axial length SL1 is 22 mm or more. In the present embodiment, the spline tooth axial length SL1 is 24.9 mm. However, the spline tooth axial length SL1 is not limited to this embodiment and the above range.

As shown in FIG. 23, the total number of at least 10 outer spline teeth 40 is 20 or more. The total number of at least 10 outer spline teeth 40 is preferably 25 or more. The total number of at least 10 outer spline teeth 40 is preferably 28 or more. The total number of outer spline teeth 40 is preferably 72 or less. In this embodiment, the total number of outer spline teeth 40 is 29. However, the total number of outer spline teeth 40 is not limited to this embodiment and the above range.

At least 10 outer spline teeth 40 have a first outer pitch angle PA11 and a second outer pitch angle PA12. At least two of the at least 10 outer spline teeth 40 are arranged at a first outer pitch angle PA11 in the circumferential direction with respect to the center of rotation A1. In other words, at least two of the plurality of outer spline teeth 40 are arranged at a first outer pitch angle PA11 in the circumferential direction with respect to the rotation center axis A1 of the bicycle rear hub assembly 12. At least two of the at least 10 outer spline teeth 40 are arranged at a second outer pitch angle PA12 in the circumferential direction with respect to the rotation center axis A1 of the bicycle rear hub assembly 12. In other words, at least two of the plurality of outer spline teeth 40 are arranged at a second outer pitch angle PA12 in the circumferential direction with respect to the rotation center axis A1 of the bicycle rear hub assembly 12. In the present embodiment, the second outer pitch angle PA12 is different from the first outer pitch angle PA11. However, the second outer pitch angle PA12 may be substantially the same as the first outer pitch angle PA11.

In this embodiment, the plurality of outer spline teeth 40 are arranged at the first outer pitch angle PA11 in the circumferential direction D1. Two of the plurality of outer spline teeth 40 are arranged at a second outer pitch angle PA12 in the circumferential direction D1. However, at least two of the outer spline teeth 40 may be arranged at other outer pitch angles in the circumferential direction D1.

The first outer pitch angle PA11 is in the range of 5 degrees to 36 degrees. The first outer pitch angle PA11 is preferably in the range of 10 to 20 degrees. The first outer pitch angle PA11 is preferably 15 degrees or less. In this embodiment, the first outer pitch angle PA11 is 12 degrees. However, the first outer pitch angle PA11 is not limited to this embodiment and the above range.

The second outer pitch angle PA12 is in the range of 5 degrees to 36 degrees. In this embodiment, the second outer pitch angle PA12 is 24 degrees. However, the second outer pitch angle PA12 is not limited to this embodiment and the above range.

At least one of the plurality of outer spline teeth 40 may have a first spline shape that is different from the other second spline shapes of the plurality of outer spline teeth 40. At least one of the at least 10 outer spline teeth 40 may have a first spline size that is different from the other second spline sizes of the at least 10 outer spline teeth 40. At least one of the plurality of outer spline teeth 40 has a contour different from the other contours of the plurality of outer spline teeth 40 when viewed along the rotation center axis A1. In this embodiment, the outer spline teeth 40X have a first spline shape that is different from the other second spline shapes of the plurality of outer spline teeth 40. The outer spline tooth 40X has a first spline size that is different from the other second spline sizes of the plurality of outer spline teeth 40. However, as shown in FIG. 24, at least 10 outer spline teeth 40 may have the same spline shape as each other. At least 10 outer spline teeth 40 may have the same spline size as each other. At least 10 outer spline teeth 40 may have the same contours as each other.

As shown in FIG. 25, each of the at least 10 outer spline teeth 40 has an outer spline drive surface 48 and an outer spline non-drive surface 50. The plurality of outer spline teeth 40 include a plurality of outer spline drive surfaces 48 for receiving a drive rotational force F1 from the bicycle rear sprocket assembly 14 (FIG. 6) during pedaling. The plurality of outer spline teeth 40 include a plurality of outer spline non-driving surfaces 50. The outer spline drive surface 48 is in contact with the bicycle rear sprocket assembly 14 for receiving the drive rotational force F1 from the bicycle rear sprocket assembly 14 (FIG. 6) during pedaling. The outer spline drive surface 48 faces the reverse rotation direction D12. The outer spline drive surface 48 faces the inner spline drive surface 66 of the bicycle rear sprocket assembly 14 with the bicycle rear sprocket assembly 14 mounted on the bicycle rear hub assembly 12. The outer spline non-driving surface 50 is provided on the opposite side of the outer spline driving surface 48 in the circumferential direction D1. The outer spline non-driving surface 50 faces the driving rotation direction D11 so as not to receive the driving rotational force F1 from the bicycle rear sprocket assembly 14 during pedaling. The outer spline non-driving surface 50 faces the inner spline non-driving surface 68 of the bicycle rear sprocket assembly 14 with the bicycle rear sprocket assembly 14 mounted on the bicycle rear hub assembly 12.

Each of the at least 10 outer spline teeth 40 has a circumferential maximum width MW1. Each of the plurality of outer spline teeth 40 has a circumferential maximum width MW1. The circumferential maximum width MW1 is defined as the maximum width so as to receive the thrust force F2 acting on the outer spline teeth 40. The circumferential maximum width MW1 is defined as a linear distance based on the outer spline drive surface 48.

Each of the plurality of outer spline drive surfaces 48 includes a radial outermost peripheral edge 48A and a radial innermost peripheral edge 48B. The outer spline drive surface 48 extends from the outermost radial edge 48A to the innermost radial edge 48B. The first reference circle RC11 is defined on the innermost peripheral edge 48B in the radial direction and is centered on the rotation center axis A1. The first reference circle RC11 intersects the outer spline non-driving surface 50 and has a reference point 50R. The maximum width MW1 in the circumferential direction extends linearly from the innermost peripheral edge 48B in the radial direction to the reference point 50R in the circumferential direction D1.

Each of the plurality of outer spline non-driving surfaces 50 includes a radial outermost peripheral edge 50A and a radial innermost peripheral edge 50B. The outer spline non-driving surface 50 extends from the outermost peripheral edge 50A in the radial direction to the innermost peripheral edge 50B in the radial direction. In this embodiment, the reference point 50R coincides with the innermost peripheral edge 50B in the radial direction. However, the reference point 50R may deviate from the innermost peripheral edge 50B in the radial direction.

The total of the maximum width MW1 in the circumferential direction is 55 mm or more. The total of the maximum width MW1 in the circumferential direction is preferably 60 mm or more. The total of the maximum width MW1 in the circumferential direction is preferably 70 mm or less. In the present embodiment, the total of the maximum width MW1 in the circumferential direction is 60.1 mm. However, the total of the maximum width MW1 in the circumferential direction is not limited to the present embodiment and the above range.

As shown in FIG. 26, at least one outer spline tooth 40 has an outer spline peak diameter DM11 of 34 mm or less. The outer spline peak diameter DM11 is 33 mm or less. The outer spline peak diameter DM11 is 29 mm or more. In this embodiment, the outer spline peak diameter DM11 is 32.6 mm. However, the outer spline peak diameter DM11 is not limited to this embodiment and the above range.

At least one outer spline tooth 40 has an outer spline valley diameter DM12. At least one outer spline tooth 40 has an outer spline root circle RC12 with an outer spline valley diameter DM12. However, the outer spline root circle RC12 may have a different diameter than the outer spline valley diameter DM12. The outer spline valley diameter DM12 is 32 mm or less. The outer spline valley diameter DM12 is 31 mm or less. The outer spline valley diameter DM12 is 28 mm or more. In the present embodiment, the outer spline valley diameter DM12 is 30.2 mm. However, the outer spline valley diameter DM12 is not limited to this embodiment and the above range.

The large diameter portion 42 has an outer diameter DM 13 larger than the outer spline peak diameter DM 11. The outer diameter DM13 is in the range of 32 mm to 40 mm. In this embodiment, the outer diameter DM13 is 35 mm. However, the outer diameter DM13 is not limited to this embodiment.

As shown in FIG. 25, each of the plurality of outer spline drive surfaces 48 includes a radial length RL11 defined from the radial outermost edge 48A to the radial innermost edge 48B. The total of the radial lengths RL11 of the plurality of outer spline drive surfaces 48 is 7 mm or more. The total length of the radial lengths RL11 is 10 mm or more. The total length of the radial lengths RL11 is 15 mm or more. The total radial length is 36 mm or less. In this embodiment, the total radial length RL11 is 16.6 mm. However, the total of the radial lengths RL11 is not limited to this embodiment.

The plurality of outer spline teeth 40 have an additional radial length RL12. Each of the additional radial lengths RL12 is defined from the outer spline root circle RC12 to the radial outermost peripheral end 40A of the plurality of outer spline teeth 40. The total length of the additional radial lengths RL12 is 20 mm or more. In this embodiment, the total length of the additional radial lengths RL12 is 31.2 mm. However, the total of the additional radial lengths RL12 is not limited to this embodiment.

At least one of the at least 10 outer spline teeth 40 is circumferentially symmetrical with respect to the reference line CL1. The reference line CL1 extends from the rotation center axis A1 of at least one radial outermost peripheral end 40A of at least 10 outer spline teeth 40 in the radial direction with respect to the rotation center axis A1 to the circumferential center point CP1. However, at least one of the plurality of outer spline teeth 40 may have an asymmetric shape with respect to the reference line CL1. At least one of the at least 10 outer spline teeth 40 comprises an outer spline drive surface 48 and an outer spline non-drive surface 50.

At least one of the plurality of outer spline drive surfaces 48 has a first outer spline surface angle AG11. The first outer spline surface angle AG11 is defined between the outer spline drive surface 48 and the first radial direction line L11. The first radial line L11 extends from the rotation center axis A1 of the bicycle rear hub assembly 12 to the outermost radial peripheral edge 48A of the outer spline drive surface 48. The first outer pitch angle PA11 or the second outer pitch angle PA12 is defined between adjacent first radial lines L11 (see, for example, FIG. 23).

At least one of the outer spline non-driving surfaces 50 has a dihedral spline surface angle AG12. The second outer spline surface angle AG12 is defined between the outer spline non-driving surface 50 and the dihedral direction line L12. The second radial line L12 extends from the rotation center axis A1 of the bicycle rear hub assembly 12 to the radial outermost peripheral edge 50A of the outer spline non-driving surface 50.

In the present embodiment, the second outer spline surface angle AG12 is equal to the first outer spline surface angle AG11. However, the first outer spline surface angle AG11 may be different from the second outer spline surface angle AG12.

The first outer spline surface angle AG11 is 6 degrees or less. The first outer spline surface angle AG11 is 0 degrees or more. The dihedral spline surface angle AG12 is 6 degrees or less. The dihedral spline surface angle AG12 is 0 degrees or more. In this embodiment, the first outer spline surface angle AG11 is 5 degrees. The dihedral spline surface angle AG12 is 5 degrees. However, the first outer spline surface angle AG11 and the second outer spline surface angle AG12 are not limited to the present embodiment and the above range.

As shown in FIGS. 27 and 28, the brake rotor support 34 includes at least one additional outer spline tooth 52 configured to engage the bicycle brake rotor 16 (FIG. 1). In this embodiment, the brake rotor support 34 includes an additional base support 54 and a plurality of additional outer spline teeth 52. The additional base support portion 54 has a tubular shape and extends from the hub body 36 along the rotation center axis A1. The additional outer spline teeth 52 extend radially outward from the additional base support 54. The total number of additional outer spline teeth 52 is 52. However, the total number of additional outer spline teeth 52 is not limited to this embodiment.

As shown in FIG. 28, at least one additional outer spline tooth 52 has an additional outer spline crest diameter DM14. As shown in FIG. 29, the additional outer spline crest diameter DM14 is larger than the outer spline crest diameter DM11. The additional outer spline peak diameter DM14 is substantially equal to the outer diameter DM13 of the large diameter portion 42. However, the additional outer spline crest diameter DM14 may be less than or equal to the outer spline crest diameter DM11. The additional outer spline peak diameter DM14 may be different from the outer diameter DM13 of the large diameter portion 42.

As shown in FIG. 29, the hub body 36 includes a first spoke mounting portion 36A and a second spoke mounting portion 36B. The plurality of first spoke SK1s are connected to the first spoke mounting portion 36A. The plurality of second spokes SK2 are connected to the second spoke attachment portion 36B. In the present embodiment, the first spoke mounting portion 36A includes a plurality of first mounting holes 36A1. The first spoke SK1 extends through the first mounting hole 36A1. The second spoke mounting portion 36B includes a plurality of second mounting holes 36B1. The second spoke SK2 extends through the second mounting hole 36B1. As used herein, the term "spoke mount" means that the spoke mount openings are flanged so that the spoke mounts extend radially outward with respect to the center of rotation of the bicycle rear hub assembly, as shown in FIG. It includes a structure having a shape and a structure in which the spoke mounting portion is an opening formed directly on the radial outer peripheral surface of the hub body.

The second spoke mounting portion 36B is separated from the first spoke mounting portion 36A in the axial direction D2. The first spoke mounting portion 36A is provided between the sprocket support 28 and the second spoke mounting portion 36B in the axial direction D2. In the axial direction D2, the second spoke mounting portion 36B is provided between the first spoke mounting portion 36A and the brake rotor support 34.

The first spoke mounting portion 36A has the outermost 36C in the first axial direction. The second spoke mounting portion 36B has the outermost 36D in the second axial direction. The outermost 36C in the first axial direction includes a surface facing the first frame BF1 in the axial direction D2 with the bicycle rear hub assembly 12 mounted on the bicycle frame BF. The outermost 36D in the second axial direction includes a surface facing the second frame BF2 in the axial direction D2 with the bicycle rear hub assembly 12 mounted on the bicycle frame BF.

The hub body 36 includes a first axial length AL1. The first axial length AL1 is the outermost 36C of the first spoke mounting portion 36A and the second outermost 36C of the second spoke mounting portion 36B in the axial direction D2 with respect to the rotation center axis A1 of the rear sprocket assembly 14 for bicycles. It is defined between the outermost 36D in the biaxial direction. The length AL1 in the first axial direction may be 55 mm or more. The length AL1 in the first axial direction may be 60 mm or more. The length AL1 in the first axial direction may be 65 mm or more. In the present embodiment, the length AL1 in the first axial direction may be 67 mm. However, the length AL1 in the first axial direction is not limited to the present embodiment and the above range. Examples of the first axial length AL1 include 55.7 mm, 62.3 mm, and 67 mm.

As shown in FIG. 29, the hub axle 30 includes a first axial frame contact surface 30B1 and a second axial frame contact surface 30C1. The first axial frame contact surface 30B1 is the bicycle frame BF in the axial direction D2 with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14 in a state where the bicycle rear hub assembly 12 is mounted on the bicycle frame BF. It is configured to come into contact with the first portion BF12. The second axial frame contact surface 30C1 is configured to contact the second portion BF22 of the bicycle frame BF in the axial direction D2 with the bicycle rear hub assembly 12 mounted on the bicycle frame BF. The first axial frame contact surface 30B1 is arranged at a position closer to the sprocket support 28 than the second axial frame contact surface 30C1 in the axial direction D2. The sprocket support 28 is provided between the first axial frame contact surface 30B1 and the second axial frame contact surface 30C1 in the axial direction D2.

The hub axle 30 includes a second axial length AL2 defined between the first axial frame contact surface 30B1 and the second axial frame contact surface 30C1 in the axial direction D2. The length AL2 in the second axial direction may be 140 mm or more. The length AL2 in the second axial direction may be 145 mm or more. The length AL2 in the second axial direction may be 147 mm or more. The length AL2 in the second axial direction may be 148 mm. However, the second axial length AL2 is not limited to this embodiment and the above range. Examples of the second axial length AL2 include 142 mm, 148 mm, and 157 mm.

The ratio of the first axial length AL1 to the second axial length AL2 may be 0.3 or more. The ratio of the first axial length AL1 to the second axial length AL2 may be 0.4 or more. The ratio of the first axial length AL1 to the second axial length AL2 may be 0.5 or less. For example, the ratio of the first axial length AL1 (67 mm) to the second axial length AL2 (148 mm) is about 0.45. However, the ratio of the first axial length AL1 to the second axial length AL2 is not limited to the present embodiment and the above range. Examples of the ratio of the first axial length AL1 to the second axial length AL2 are about 0.42 (AL1 is 62.3 mm and AL2 is 148 mm) and about 0.39 (AL1 is 55). .7 mm and AL2 is 142 mm).

As shown in FIG. 6, the sprocket support 28 has a first axial end 28B, a second axial end 28C, and a sprocket axial contact surface 28D. The second axial end 28C is arranged on the opposite side of the first axial end 28B in the axial D2. The axial center plane CPL bisects the second axial length AL2 in the axial direction D2. The sprocket axial contact surface 28D is arranged at a position closer to the axial central surface CPL of the bicycle rear hub assembly 12 than the first axial end 28B in the axial direction D2. The second axial end 28C is arranged at a position closer to the axial central surface CPL of the bicycle rear hub assembly 12 than the sprocket axial contact surface 28D in the axial direction D2. The sprocket axial contact surface 28D is provided on the large diameter portion 42 in this embodiment, whereas the sprocket axial contact surface 28D is provided on the other portion of the bicycle rear hub assembly 12 as needed. It may be provided. The sprocket axial contact surface 28D is in contact with the bicycle rear sprocket assembly 14 with the bicycle rear sprocket assembly 14 mounted on the sprocket support 28. The sprocket axial contact surface 28D faces the first axial end 28B in the axial direction D2.

As shown in FIG. 6, in the axial direction D2, the sprocket arrangement axial length AL3 is defined between the first axial frame contact surface 30B1 of the sprocket support 28 and the sprocket axial contact surface 28D. In the present embodiment, the sprocket arrangement axial length AL3 is in the range of 35 mm to 45 mm. For example, the sprocket arrangement axial length AL3 is 39.64 mm. The sprocket arrangement axial length AL3 can be extended to 44.25 mm, for example, by omitting the large diameter portion 42. However, the sprocket arrangement axial length AL3 is not limited to this embodiment and the above range.

The large diameter portion 42 has an axial end portion 42A farthest from the first axial frame contact surface 30B1 in the axial direction D2. In the axial direction D2, an additional axial length AL4 is defined from the first axial frame contact surface 30B1 to the axial end 42A. The additional axial length AL4 is in the range of 38 mm to 47 mm. The additional axial length AL4 may be in the range of 44 mm to 45 mm. Further, the additional axial length AL4 may be in the range of 40 mm to 41 mm. In this embodiment, the additional axial length AL4 is 44.25 mm. However, the additional axial length AL4 is not limited to this embodiment and the above range.

The large-diameter axial length AL5 of the large-diameter portion 42 is in the range of 3 mm to 6 mm. In the present embodiment, the large-diameter axial length AL5 is 4.61 mm. However, the large-diameter axial length AL5 is not limited to this embodiment and the above range.

The ratio of the first axial length AL1 to the sprocket arrangement axial length AL3 is in the range of 1.2 to 1.7. For example, the ratio of the first axial length AL1 to the sprocket placement axial length AL3 is when the first axial length AL1 is 55.7 mm and the sprocket placement axial length AL3 is 39.64 mm. Is 1.4. However, the ratio of the first axial length AL1 to the sprocket arrangement axial length AL3 is not limited to the present embodiment and the above range. For example, the ratio of the first axial length AL1 to the sprocket placement axial length AL3 is when the first axial length AL1 is 62.3 mm and the sprocket placement axial length AL3 is 39.64 mm. Can be 1.57, or the ratio of the first axial length AL1 to the sprocket placement axial length AL3 is that the first axial length AL1 is 67 mm and the sprocket placement axial length AL3 is. If it is 39.64 mm, it may be 1.69.

As shown in FIG. 30, the sprocket support member 37 includes a hub engaging portion 60 and a plurality of support arms 62. The plurality of support arms 62 extend outward from the hub engaging portion 60 to the radial direction. The support arm 62 includes first to eighth mounting portions 62A to 62H. The plurality of spacers 38 include a plurality of first spacers 38A, a plurality of second spacers 38B, a plurality of third spacers 38C, a plurality of fourth spacers 38D, a plurality of fifth spacers 38E, and a plurality of sixth spacers. A spacer 38F and a plurality of seventh spacers 38G are included.

As shown in FIG. 6, the first spacer 38A is provided between the additional sprockets SP5 and SP6. The second spacer 38B is provided between the additional sprockets SP6 and SP7. The third spacer 38C is provided between the additional sprockets SP7 and SP8. The fourth spacer 38D is provided between the additional sprockets SP8 and SP9. The fifth spacer 38E is provided between the additional sprockets SP9 and SP10. The sixth spacer 38F is provided between the additional sprockets SP10 and SP11. The seventh spacer 38G is provided between the additional sprockets SP11 and SP12.

The additional sprocket SP6 and the first spacer 38A are attached to the first attachment portion 62A by the adhesive 37A. The additional sprocket SP7 and the second spacer 38B are attached to the second attachment portion 62B by the adhesive 37A. The additional sprocket SP8 and the third spacer 38C are attached to the third attachment portion 62C by the adhesive 37A. The additional sprocket SP9 and the fourth spacer 38D are attached to the fourth attachment portion 62D by the adhesive 37A. The additional sprocket SP10 and the fifth spacer 38E are attached to the fifth attachment portion 62E by the adhesive 37A. The additional sprocket SP11 and the sixth spacer 38F are attached to the sixth attachment portion 62F by the adhesive 37A. The additional sprocket SP12 and the seventh spacer 38G are attached to the seventh attachment portion 62G by the adhesive 37A. The additional sprocket SP5 and the second ring 39B are attached to the eighth attachment portion 62H by the adhesive 37A. The hub engaging portion 60, the sprockets SP1 to SP4, the first ring 39A, and the second ring 39B are held between the large diameter portion 42 and the radial projection 32C of the lock member 32 in the axial direction D2.

In this embodiment, each of the sprockets SP1 to SP12 is composed of a metal material such as aluminum, iron, and titanium. The sprocket support member 37 is made of a non-metal material including a resin material. Each of the first to seventh spacers 38A to 38G, the first ring 39A, and the second ring 39B is composed of a non-metallic material such as a resin material. However, at least one of the sprockets SP1 to SP12 may be at least partially composed of a non-metallic material. At least one of the sprocket support members 37, the first to seventh spacers 38A-38G, the first ring 39A, and the second ring 39B is at least partially composed of a metallic material such as aluminum, iron, or titanium. May be.

As shown in FIG. 7, the first sprocket SP1 includes a first opening SP1K. The first opening SP1K has a first minimum diameter MD1. As shown in FIG. 31, the tubular portion 32A of the lock member 32 extends through the first opening SP1K of the first sprocket SP1 with the bicycle rear sprocket assembly 14 mounted on the sprocket support 28. In the first opening SP1K of the first sprocket SP1, the first axial end 32D of the tubular portion 32A of the lock member 32 is the first sprocket SP1 in a state where the bicycle rear sprocket assembly 14 is mounted on the sprocket support 28. It is configured to pass through the first opening SP1K of. The first axial end 28B of the sprocket support 28 is separated from the first opening SP1K of the first sprocket SP1 without extending through the first opening SP1K. The first minimum diameter MD1 is smaller than the minimum outer diameter MD28 of the sprocket support 28 of the bicycle rear hub assembly 12. In this embodiment, the minimum outer diameter MD28 is equal to the outer spline valley diameter DM12 of the plurality of outer spline teeth 40 of the sprocket support 28 (FIG. 26).

As shown in FIG. 31, the tubular portion 32A has a first outer diameter ED1 of 27 mm or less. The first outer diameter ED1 is 26 mm or more. The radial protrusion 32C has a second outer diameter ED2 of 32 mm or less. The second outer diameter ED2 is 30 mm or more. In the present embodiment, the first outer diameter ED1 is 26.2 mm. The second outer diameter ED2 is 30.8 mm. However, at least one of the first outer diameter ED1 and the second outer diameter ED2 is not limited to the present embodiment and the above range.

The radial protrusion 32C has an axial width ED3 defined in the axial direction D2. For example, the axial width ED3 of the radial protrusion 32C is 2 mm. However, the axial width ED3 is not limited to this embodiment.

The lock member 32 has an axial length ED4 defined from the radial protrusion 32C to the first axial end 32D in the axial direction D2. The axial length ED4 of the lock member 32 is 10 mm. However, the axial length ED4 is not limited to this embodiment.

As shown in FIG. 8, the first sprocket SP2 includes a first opening SP2K. That is, each of the plurality of first sprockets SP1 and SP2 includes a first opening SP2K. The first opening SP2K has a first minimum diameter MD2. As shown in FIG. 31, the tubular portion 32A of the lock member 32 extends through the first opening SP2K of the first sprocket SP2 with the bicycle rear sprocket assembly 14 mounted on the sprocket support 28. The first axial end 28B of the sprocket support 28 is separated from the first opening SP2K of the first sprocket SP2 without extending through the first opening SP2K. The first minimum diameter MD2 is smaller than the minimum outer diameter MD28 of the sprocket support 28 of the bicycle rear hub assembly 12.

As shown in FIG. 9, the second sprocket SP3 includes a second opening SP3K. The second opening SP3K has a second minimum diameter MD3. As shown in FIG. 31, the tubular portion 32A of the lock member 32 and the sprocket support 28 have a second opening SP3K of the second sprocket SP3 with the bicycle rear sprocket assembly 14 mounted on the sprocket support 28. Extend through. The first axial end 28B of the sprocket support 28 is provided between the second opening SP3K and the first opening SP1K in the axial direction D2. The first axial end 28B of the sprocket support 28 is provided between the second opening SP3K and the first opening SP2K in the axial direction D2. The second minimum diameter MD3 is equal to or larger than the minimum outer diameter MD28 of the sprocket support 28 of the bicycle rear hub assembly 12.

As shown in FIG. 10, the second sprocket SP4 includes a second opening SP4K. That is, each of the plurality of second sprockets SP3 and SP4 includes a second opening SP4K. The second opening SP4K has a second minimum diameter MD4. As shown in FIG. 31, the sprocket support 28 extends through the second opening SP4K of the second sprocket SP4 with the bicycle rear sprocket assembly 14 mounted on the sprocket support 28. The first axial end 28B of the sprocket support 28 is provided between the second opening SP4K and the first opening SP1K in the axial direction D2. The second minimum diameter MD4 is equal to or larger than the minimum outer diameter MD28 of the sprocket support 28 of the bicycle rear hub assembly 12.

As shown in FIG. 32, the first sprocket SP2 includes at least 10 inner spline teeth 63 configured to engage the sprocket support 28 of the bicycle rear hub assembly 12. At least 10 inner spline teeth 63 are provided in the first opening SP2K. At least 10 inner spline teeth 63 are provided as a first torque transmission structure of the first sprocket SP2 as described later.

The total number of at least 10 inner spline teeth 63 of the first sprocket SP2 is 20 or more. The total number of at least 10 inner spline teeth 63 of the first sprocket SP2 is 28 or more. The total number of medial spline teeth 63 is 72 or less. In this embodiment, the total number of inner spline teeth 63 is 29. However, the total number of medial spline teeth 63 is not limited to this embodiment and the above range.

As shown in FIG. 9, the second sprocket SP3 includes at least 10 inner spline teeth 64 configured to engage the sprocket support 28 of the bicycle rear hub assembly 12. In this embodiment, at least 10 inner spline teeth 64 of the second sprocket SP3 define a second minimum diameter MD3 as the inner spline crest diameter of at least 10 inner spline teeth 64.

The total number of at least 10 inner spline teeth 64 of the second sprocket SP3 is 20 or more. The total number of at least 10 inner spline teeth 64 of the second sprocket SP3 is 28 or more. The total number of inner spline teeth 64 is 72 or less. In this embodiment, the total number of inner spline teeth 64 is 29. However, the total number of inner spline teeth 64 is not limited to this embodiment and the above range.

As shown in FIG. 10, the second sprocket SP4 includes at least 10 inner spline teeth 65 configured to engage the sprocket support 28 of the bicycle rear hub assembly 12. That is, each of the plurality of second sprockets SP3 and SP4 includes at least 10 inner spline teeth configured to engage the sprocket support 28 of the bicycle rear hub assembly 12. In the present embodiment, at least 10 inner spline teeth 65 of the second sprocket SP4 define a second minimum diameter MD4 as the inner spline peak diameter of at least 10 inner spline teeth 65.

The total number of at least 10 inner spline teeth 65 of the second sprocket SP4 is 20 or more. The total number of at least 10 inner spline teeth 65 of the second sprocket SP4 is 28 or more. The total number of medial spline teeth 65 is 72 or less. In this embodiment, the total number of inner spline teeth 65 is 29. However, the total number of inner spline teeth 65 is not limited to this embodiment and the above range.

As shown in FIG. 33, at least 10 inner spline teeth 64 of the second sprocket SP3 have a first inner pitch angle PA21 and a second inner pitch angle PA22. At least two of the at least two inner spline teeth 64 of the second sprocket SP3 are arranged at the first inner pitch angle PA21 in the circumferential direction with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. Will be done. At least two of the at least 10 medial spline teeth 64 are adjacent to each other in the circumferential direction D1 without any other spline teeth in between. In other words, at least two of the plurality of inner spline teeth 64 are arranged at the first inner pitch angle PA21 in the circumferential direction with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. At least the other two inner spline teeth of the at least 10 inner spline teeth 64 of the second sprocket SP3 are arranged at a second inner pitch angle PA22 in the circumferential direction with respect to the center of rotation A1. At least the other two inner spline teeth of the at least 10 inner spline teeth 64 of the second sprocket SP3 are adjacent to each other in the circumferential direction D1 without any other spline teeth in between. In other words, at least two of the plurality of inner spline teeth 64 of the second sprocket SP3 are arranged at the second inner pitch angle PA22 in the circumferential direction with respect to the rotation center axis A1. In the present embodiment, the second inner pitch angle PA22 is different from the first inner pitch angle PA21. However, the second inner pitch angle PA22 may be substantially the same as the first inner pitch angle PA21.

In the present embodiment, the plurality of inner spline teeth 64 are arranged in the circumferential direction at the first inner pitch angle PA21 in the circumferential direction D1. Two of the plurality of inner spline teeth 64 are arranged at the second inner pitch angle PA22 in the circumferential direction D1. However, at least two of the plurality of inner spline teeth 64 may be arranged at other inner pitch angles in the circumferential direction D1.

The first inner pitch angle PA21 is in the range of 5 degrees to 36 degrees. The first inner pitch angle PA21 is in the range of 10 degrees to 20 degrees. The first inner pitch angle PA21 is 15 degrees or less. In the present embodiment, for example, the first inner pitch angle PA21 is 12 degrees. However, the first inner pitch angle PA21 is not limited to this embodiment and the above range.

The second inner pitch angle PA22 is in the range of 5 to 36 degrees. In this embodiment, the second inner pitch angle PA22 is 24 degrees. However, the second inner pitch angle PA22 is not limited to this embodiment and the above range.

At least one of the at least 10 inner spline teeth 64 of the second sprocket SP3 has a first spline shape that is different from the other second spline shapes of the at least 10 inner spline teeth 64. At least one of the at least 10 inner spline teeth 64 of the second sprocket SP3 has a first spline size that is different from the other second spline sizes of the at least 10 inner spline teeth 64. At least one of the at least 10 inner spline teeth 64 has a cross-sectional shape different from the other cross-sectional shapes of the at least 10 inner spline teeth 64. However, as shown in FIG. 34, the plurality of inner spline teeth 64 may have the same shape as each other. At least 10 inner spline teeth 64 may have the same size as each other. At least 10 inner spline teeth 64 may have the same cross-sectional shape to each other.

As shown in FIG. 35, at least one of the at least 10 inner spline teeth 64 includes an inner spline drive surface 66. At least one of the at least 10 inner spline teeth 64 includes an inner spline non-driving surface 68. At least 10 inner spline teeth 64 include a plurality of inner spline drive surfaces 66 to receive drive rotational force F1 from the bicycle rear hub assembly 12 (FIG. 6) during pedaling. At least 10 inner spline teeth 64 include a plurality of inner spline non-driving surfaces 68. The inner spline drive surface 66 is in contact with the sprocket support 28 so as to transmit the drive rotational force F1 from the sprocket SP1 to the sprocket support 28 during pedaling. The inner spline drive surface 66 faces the drive rotation direction D11. The inner spline drive surface 66 faces the outer spline drive surface 48 of the bicycle rear hub assembly 12 with the bicycle rear sprocket assembly 14 mounted on the bicycle rear hub assembly 12. The inner spline non-driving surface 68 is provided on the opposite side of the inner spline driving surface 66 in the circumferential direction D1. The inner spline non-driving surface 68 faces the reverse rotation direction D12 so as not to transmit the driving rotational force F1 from the sprocket SP1 to the sprocket support 28 during pedaling. The inner spline non-driving surface 68 faces the outer spline non-driving surface 50 of the bicycle rear hub assembly 12 with the bicycle rear sprocket assembly 14 mounted on the bicycle rear hub assembly 12.

Each of the at least 10 inner spline teeth 64 has a circumferential maximum width MW2. Each of the plurality of inner spline teeth 64 has a circumferential maximum width MW2. The circumferential maximum width MW2 is defined as the maximum width to receive the thrust force F3 applied to the inner spline teeth 64. The circumferential maximum width MW2 is defined as a linear distance based on the inner spline drive surface 66.

Each of the plurality of inner spline drive surfaces 66 includes a radial outermost peripheral edge 66A and a radial innermost peripheral edge 66B. The second reference circle RC21 is defined on the outermost peripheral edge 66A in the radial direction and is centered on the rotation center axis A1. The second reference circle RC21 intersects the inner spline non-driving surface 68 and has a reference point 68R. The circumferential maximum width MW2 extends straight from the radial innermost peripheral edge 66B to the reference point 68R in the circumferential direction D1.

The inner spline non-driving surface 68 includes a radial outermost peripheral edge 68A and a radial innermost peripheral edge 68B. The inner spline non-driving surface 68 extends from the outermost radial edge 68A to the innermost radial edge 68B. The reference point 68R is provided between the outermost peripheral edge 68A in the radial direction and the innermost peripheral edge 68B in the radial direction.

The total of the maximum width MW2 in the circumferential direction is 40 mm or more. The total of the maximum width MW2 in the circumferential direction may be 45 mm or more. The total of the maximum width MW2 in the circumferential direction may be 50 mm or more. In the present embodiment, the total of the maximum width MW2 in the circumferential direction is 50.8 mm. However, the total of the maximum width MW2 in the circumferential direction is not limited to this embodiment.

As shown in FIG. 36, at least 10 inner spline teeth 64 of the second sprocket SP3 have an inner spline valley diameter DM21. At least one inner spline tooth 64 of the sprocket SP3 has an inner spline root circle RC22 with an inner spline valley diameter DM21. The inner spline valley diameter DM21 is 34 mm or less. The inner spline valley diameter DM21 of the second sprocket SP3 is 33 mm or less. The inner spline valley diameter DM21 of the second sprocket SP3 is 29 mm or more. In the present embodiment, the inner spline valley diameter DM21 of the second sprocket SP3 is 32.8 mm. However, the inner spline valley diameter DM21 of the second sprocket SP3 is not limited to this embodiment and the above range.

At least 10 inner spline teeth 64 of the second sprocket SP3 have an inner spline crest diameter DM22 of 32 mm or less. The inner spline peak diameter DM22 is 31 mm or less. The inner spline peak diameter DM22 is 28 mm or more. In the present embodiment, the inner spline peak diameter DM22 is 30.4 mm. However, the inner spline peak diameter DM22 is not limited to this embodiment and the above range.

As shown in FIG. 18, the additional sprocket SP12 has a maximum tooth tip diameter TD12. The maximum tooth tip diameter TD12 is the maximum outer diameter defined by the plurality of sprocket teeth SP12B. The ratio of the inner spline valley diameter DM21 (FIG. 36) to the maximum tooth tip diameter TD12 is in the range of 0.15 to 0.18. In this embodiment, the ratio of the inner spline valley diameter TD12 to the maximum tooth tip diameter TD21 is 0.15. However, the ratio of the inner spline valley diameter DM21 to the maximum tooth tip diameter TD12 is not limited to this embodiment and the above range.

As shown in FIG. 35, the plurality of inner spline drive surfaces 66 include a radial outermost peripheral edge 66A and a radial innermost peripheral edge 66B. Each of the plurality of inner spline drive surfaces 66 includes a radial length RL21 defined from the radial outermost edge 66A to the radial innermost edge 66B. The total of the radial lengths RL21 of the plurality of inner spline drive surfaces 66 is 7 mm or more. The total length of the radial lengths RL21 is 10 mm or more. The total length of the radial lengths RL21 is 15 mm or more. The total length of the radial length RL21 is 36 mm or less. In the present embodiment, the total length RL21 in the radial direction is 16.6 mm. However, the sum of the radial lengths RL21 is not limited to this embodiment and the above range.

The plurality of inner spline teeth 64 have an additional radial length RL22. Each of the additional radial lengths RL22 is defined from the inner spline root circle RC22 of the plurality of inner spline teeth 64 to the radial innermost peripheral end 64A. The total length of the additional radial lengths RL22 is 12 mm or more. In this embodiment, the total additional radial length RL22 is 34.8 mm. However, the sum of the additional radial lengths RL22 is not limited to this embodiment and the above range.

At least one of the at least 10 inner spline teeth 64 of the second sprocket SP3 is circumferentially symmetrical with respect to the reference line CL2. The reference line CL2 is a circumferential center point CP2 of at least one of at least 10 inner spline teeth 64 in the radial direction with respect to the rotation center axis A1 from the rotation center axis A1. Extends to. However, at least one of the plurality of inner spline teeth 64 may have an asymmetric shape with respect to the reference line CL2. At least one of the inner spline teeth 64 has an inner spline drive surface 66 and an inner spline non-drive surface 68.

The inner spline drive surface 66 has a first inner spline surface angle AG21. The first inner spline surface angle AG21 is defined between the inner spline drive surface 66 and the first radial direction line L21. The first radial line L21 extends from the rotation center axis A1 of the bicycle rear sprocket assembly 14 to the radial outermost peripheral edge 66A of the inner spline drive surface 66. The first inner pitch angle PA21 or the second inner pitch angle PA22 is defined between adjacent first radial lines L21 (see, for example, FIG. 33).

The inner spline non-driving surface 68 has a dihedral spline surface angle AG22. The second inner spline surface angle AG22 is defined between the inner spline non-driving surface 68 and the dihedral direction line L22. The second radial line L22 extends from the rotation center axis A1 of the bicycle rear sprocket assembly 14 to the radial outermost peripheral edge 68A of the inner spline non-driving surface 68.

In the present embodiment, the second inner spline surface angle AG22 is equal to the first inner spline surface angle AG21. However, the first inner spline surface angle AG21 may be different from the second inner spline surface angle AG22.

The first inner spline surface angle AG21 is in the range of 0 degrees to 6 degrees. The dihedral spline surface angle AG22 is in the range of 0 to 6 degrees. In this embodiment, the first inner spline surface angle AG21 is 5 degrees. The dihedral spline surface angle AG22 is 5 degrees. However, the first inner spline surface angle AG21 and the second inner spline surface angle AG22 are not limited to the present embodiment and the above range.

As shown in FIG. 37, the plurality of inner spline teeth 64 mesh with the plurality of outer spline teeth 40 so as to transmit the driving rotational force F1 from the second sprocket SP3 to the sprocket support 28. The inner spline drive surface 66 is in contact with the outer spline drive surface 48 so as to transmit the drive rotational force F1 from the second sprocket SP3 to the sprocket support 28. The inner spline non-driving surface 68 is separated from the outer spline non-driving surface 50 in a state where the inner spline driving surface 66 is in contact with the outer spline driving surface 48.

The plurality of inner spline teeth 63 of the first sprocket SP2 and the plurality of inner spline teeth 65 of the second sprocket SP4 have substantially the same mechanism as the plurality of inner spline teeth 64 of the second sprocket SP3. Therefore, for the sake of brevity, detailed description thereof will be omitted here.

As shown in FIG. 2, the sprocket support member 37 includes at least 10 inner spline teeth 76 configured to engage the sprocket support 28 of the bicycle rear hub assembly 12. The plurality of medial spline teeth 76 have substantially the same mechanism as the plurality of medial spline teeth 64. Therefore, for the sake of brevity, detailed description thereof will be omitted here.

As shown in FIG. 38, the first sprocket SP1 includes a first torque transmission structure SP1T provided on the first inner side surface SP1H so as to directly or indirectly transmit pedaling torque to the sprocket support 28. In the present embodiment, the first torque transmission structure SP1T includes a plurality of first torque transmission teeth SP1T1 so as to indirectly transmit pedaling torque to the sprocket support 28. The first torque transmission structure SP1T includes at least 10 first torque transmission teeth SP1T1. Preferably, the total number of at least 10 first torque transmission teeth SP1T1 is 20 or more. More preferably, the total number of at least 10 first torque transmission teeth SP1T1 is 28 or more. In the present embodiment, the total number of at least 10 first torque transmission teeth SP1T1 is 29. However, the total number of at least 10 first torque transmission teeth SP1T1 is not limited to this embodiment and the above range.

As shown in FIGS. 38 and 39, the first sprocket SP2 includes a first inner side surface SP2H and a first outer side surface SP2G. The first outer side surface SP2G is arranged on the opposite side of the first inner side surface SP2H in the axial direction D2 with respect to the rotation center axis A1 of the bicycle rear sprocket assembly 14. The first sprocket SP2 includes a first torque transmission structure SP2M provided on the first inner side surface SP2H so as to directly or indirectly transmit pedaling torque to the sprocket support 28. In the present embodiment, the inner spline tooth 63 of the first sprocket SP2 can also be referred to as the first torque transmission tooth 63. The first torque transmission structure SP2M includes a plurality of first torque transmission teeth 63 so as to directly transmit pedaling torque to the sprocket support 28. The first torque transmission structure SP2M includes at least 10 first torque transmission teeth 63. Preferably, the total number of at least 10 first torque transmission teeth 63 is 20 or more. More preferably, the total number of at least 10 first torque transmission teeth 63 is 28 or more. In the present embodiment, the total number of at least 10 first torque transmission teeth 63 is 29. However, the total number of at least 10 first torque transmission teeth 63 is not limited to the above embodiment and the above range. The first torque transmission tooth 63 can also be referred to as the medial spline tooth 63.

As shown in FIG. 39, the first sprocket SP2 includes a second torque transmission structure SP2T so as to receive pedaling torque from the first sprocket SP1. The second torque transmission structure SP2T is provided on the first outer side surface SP2G. In the present embodiment, the second torque transmission structure SP2T includes a plurality of second torque transmission teeth SP2T1. Preferably, the total number of the second torque transmission teeth SP2T1 is 20 or more. More preferably, the total number of the second torque transmission teeth SP2T1 is 28 or more. In the present embodiment, the total number of the second torque transmission teeth SP2T1 is 29. However, the total number of the second torque transmission teeth SP2T1 is not limited to this embodiment and the above range. The first torque transmission structure SP1T is engaged with the second torque transmission structure SP2T. The plurality of first torque transmission teeth SP1T1 mesh with the plurality of second torque transmission teeth SP2T1 so as to transmit the driving rotational force F1.

As shown in FIGS. 23 and 24, the sprocket support 28 includes a hub display 28I provided at the axial end of the base support 41. The hub display unit 28I is provided in the region of the second outer pitch angle PA12 when viewed along the rotation center axis A1. In this embodiment, the hub display unit 28I includes dots. However, the hub display 28I may include other shapes such as triangles and lines. Further, the hub display 28I may be a separate member attached to the sprocket support 28 by a coupling mechanism such as an adhesive. The position of the hub display unit 28I is not limited to this embodiment.

As shown in FIG. 7, the first sprocket SP1 includes a sprocket display portion SP1I provided at an axial end portion of the sprocket body SP1A. In the present embodiment, the sprocket display unit SP1I includes dots. However, the sprocket display unit SP1I may include other shapes such as triangles and lines. Further, the sprocket display unit SP1I may be a separate member attached to the sprocket SP1 by a bonding mechanism such as an adhesive. The position of the sprocket display unit SP1I is not limited to this embodiment. The sprocket display unit SP1I may be provided on any of the other sprockets SP2 to SP12. The sprocket display unit SP1I may also be provided on the sprocket support member 37.

As shown in FIG. 6, the bicycle rear hub assembly 12 further includes a freewheel mechanism 78. The sprocket support 28 is operably connected to the hub body 36 by a freewheel mechanism 78. The freewheel mechanism 78 is configured to connect the sprocket support 28 to the hub body 36 so as to rotate the sprocket support 28 together with the hub body 36 in the drive rotation direction D11 (FIG. 5) during pedaling. The freewheel mechanism 78 is configured to allow the sprocket support 28 to rotate with respect to the hub body 36 in the reverse rotation direction D12 (FIG. 5) during coasting. Therefore, the freewheel mechanism 78 may be paraphrased as a one-way clutch mechanism 78. The freewheel mechanism 78 will be described in detail later.

The bicycle rear hub assembly 12 includes a first bearing 79A and a second bearing 79B. The first bearing 79A and the second bearing 79B are provided between the sprocket support 28 and the hub axle 30 so as to rotatably support the sprocket support 28 with respect to the hub axle 30 around the center of rotation A1.

In this embodiment, each of the sprocket support 28, the brake rotor support 34, and the hub body 36 is made of a metal material such as aluminum, iron, or titanium. However, at least one of the sprocket support 28, the brake rotor support 34, and the hub body 36 may be made of a non-metallic material.

As shown in FIG. 40, the freewheel mechanism 78 includes a first ratchet member 80 and a second ratchet member 82. The first ratchet member 80 is configured to engage with one of the hub body 36 and the sprocket support 28 in a torque transmission manner. The second ratchet member 82 is configured to engage with the other of the hub body 36 and the sprocket support 28 in a torque transmission manner. In this embodiment, the first ratchet member 80 engages with the sprocket support 28 in a torque transmission manner. The second ratchet member 82 engages with the hub body 36 on the torque transmission side surface. However, the first ratchet member 80 may be configured to engage with the hub body 36 in a torque transmission system. The second ratchet member 82 may be configured to engage the sprocket support 28 in a torque transmission manner.

The first ratchet member 80 is attached to the sprocket support 28 so as to rotate with the sprocket support 28 with respect to the hub body 36 around the rotation center axis A1. The second ratchet member 82 is attached to the hub body 36 so as to rotate together with the hub body 36 with respect to the sprocket support body 28 around the rotation center axis A1. Each of the first ratchet member 80 and the second ratchet member 82 has a ring shape.

At least one of the first ratchet member 80 and the second ratchet member 82 is movable with respect to the hub axle 30 in the axial direction D2 with respect to the rotation center axis A1. In this embodiment, each of the first ratchet member 80 and the second ratchet member 82 is movable with respect to the hub axle 30 in the axial direction D2. The second ratchet member 82 is movable with respect to the hub body 36 in the axial direction D2. The first ratchet member 80 is movable with respect to the sprocket support 28 in the axial direction D2.

The hub body 36 includes a freewheel housing 36H having a ring shape. The freewheel housing 36H extends in the axial direction D2. The first ratchet member 80 and the second ratchet member 82 are provided in the freewheel housing 36H in an assembled state.

As shown in FIG. 41, the first ratchet member 80 includes at least one first ratchet tooth 80A. In the present embodiment, at least one first ratchet tooth 80A includes a plurality of first ratchet teeth 80A. The plurality of first ratchet teeth 80A are arranged in the circumferential direction D1 so as to provide a serrated shape.

As shown in FIG. 42, the second ratchet member 82 includes at least one second ratchet tooth 82A configured to engage at least one first ratchet tooth 80A in a torque transmission manner. At least one second ratchet tooth 82A engages with at least one first ratchet tooth 80A so as to transmit a rotational force F1 from the sprocket support 28 to the hub body 36 (FIG. 40). In the present embodiment, at least one second ratchet tooth 82A includes a plurality of second ratchet teeth 82A configured to engage the plurality of first ratchet teeth 80A in a torque transmission manner. The plurality of second ratchet teeth 82A are arranged in the circumferential direction D1 so as to provide saw teeth. The plurality of second ratchet teeth 82A can engage with the plurality of first ratchet teeth 80A. The first ratchet member 80 and the second ratchet member 82 rotate together in a state where the plurality of second ratchet teeth 82A are engaged with the plurality of first ratchet teeth 80A.

As shown in FIGS. 41 and 42, the sprocket support 28 has an outer peripheral surface 28P having a first helical spline 28H. The first ratchet member 80 is configured to engage the sprocket support 28 in a torque transmission manner and includes a second helical spline 80H that meshes with the first helical spline 28H. The first ratchet member 80 moves in the axial direction D2 with respect to the sprocket support 28 via the second helical spline 80H that meshes with the first helical spline 28H during driving by the first thrust force applied from the sprocket support 28. Can be installed. In this embodiment, the first helical spline 28H includes a plurality of outer helical spline teeth 46. The second helical spline 80H includes a plurality of inner helical spline teeth 80H1 that mesh with the plurality of outer helical spline teeth 46.

As shown in FIG. 43, the hub body 36 includes an inner peripheral surface 36S and at least one first tooth 36T. At least one first tooth 36T is provided on the inner peripheral surface 36S. In this embodiment, the freewheel housing 36H includes an inner peripheral surface 36S. The hub body 36 includes a plurality of first teeth 36T. The plurality of first teeth 36T are provided on the inner peripheral surface 36S and extend radially inward from the inner peripheral surface 36S with respect to the rotation center axis A1. The plurality of first teeth 36T are arranged in the circumferential direction D1 so as to define a plurality of recesses 36R between two adjacent teeth of the plurality of first teeth 36T.

The second ratchet member 82 is engaged with the hub body 36 by a torque transmission method so as to transmit the rotational force F1 from the first ratchet member 80 to the hub body 36 via the hub body engaging portion 82E. Includes ratchet 82E. One of the hub body engaging portion 82E and the hub body 36 includes at least one protrusion extending in the radial direction. The other of the hub body engaging portion 82E and the hub body 36 includes at least one recess that is engaged with at least one protrusion. In the present embodiment, the hub body engaging portion 82E includes at least one protrusion 82T extending in the radial direction as at least one protrusion. The hub body 36 includes at least one recess 36R that is engaged with at least one protrusion 82T. In the present embodiment, the hub body engaging portion 82E includes a plurality of protrusions 82T. The plurality of protrusions 82T are engaged with the plurality of recesses 36R.

As shown in FIG. 42, the outer peripheral surface 28P of the sprocket support 28 has a guide portion 28G configured to guide the first ratchet member 80 toward the hub body 36 during coasting. The guide portion 28G is arranged so as to define the first helical spline 28H and the obtuse angle AG28 (FIG. 48). The sprocket support 28 includes a plurality of guide portions 28G. The guide portion 28G is configured to guide the first ratchet member 80 toward the hub body 36 during inertia or freewheeling. The guide portion 28G first toward the hub body 36 so as to release the meshing engagement with at least one first ratchet tooth 80A (FIG. 41) and at least one second ratchet tooth 82A during coasting. Guide the ratchet member 80. The guide portion 28G is configured to move the first ratchet member 80 away from the second ratchet member 82 in the axial direction D2. The guide portion 28G extends at least in the circumferential direction D1 with respect to the sprocket support 28. The guide portion 28G extends from one of the plurality of outer helical spline teeth 46 at least in the circumferential direction D1. Although the guide portion 28G is provided integrally with the outer helical spline teeth 46 as one single member in the present embodiment, the guide portion 28G may be a member separate from the plurality of outer helical spline teeth 46. The first ratchet member 80 and the second ratchet member 82 are arranged from each other during coasting due to the guide portion 28G, especially when the guide portion 28G is arranged to define an obtuse angle AG28 with respect to the first helical spline 28H. Smoothly disengaged. It also reduces noise during inertia because at least one first ratchet tooth 80A and at least one second ratchet tooth 82A are smoothly separated during coasting.

As shown in FIG. 40, the bicycle rear hub assembly 12 further includes an urging member 84. The urging member 84 is arranged between the hub body 36 and the first ratchet member 80 so as to urge the first ratchet member 80 in the axial direction D2 toward the second ratchet member 82. In this embodiment, for example, the urging member 84 is a compression spring.

As shown in FIG. 44, the urging member 84 is compressed between the hub body 36 and the first ratchet member 80 in the axial direction D2. The urging member 84 maintains an engaged state in which the first ratchet member 80 and the second ratchet member 82 are engaged with each other via the plurality of first ratchet teeth 80A and the plurality of second ratchet teeth 82A. 2 The first ratchet member 80 is urged toward the ratchet member 82.

Preferably, the urging member 84 is engaged with the hub body 36 so as to rotate with the hub body 36. The urging member 84 is attached to the hub body 36 so as to rotate with the hub body 36 around the rotation center axis A1 (FIG. 40). The urging member 84 includes a coil body 84A and a connecting end 84B. The hub body 36 includes a connection hole 36F. The connecting end portion 84B is provided in the connecting hole 36F so that the urging member 84 rotates together with the hub body 36 around the rotation center axis A1 (FIG. 40).

As shown in FIG. 44, the outer peripheral surface 28P of the sprocket support 28 supports the first ratchet member 80 and the second ratchet member 82. The first ratchet member 80 includes an axial surface 80S facing the axial direction D2. At least one first ratchet tooth 80A is arranged on the axial surface 80S of the first ratchet member 80. In the present embodiment, the plurality of first ratchet teeth 80A are arranged on the axial surface 80S of the first ratchet member 80. The axial plane 80S is substantially perpendicular to the axial direction D2. However, the axial plane 80S may be non-perpendicular to the axial D2.

The second ratchet member 82 includes an axial surface 82S facing the axial direction D2. At least one second ratchet tooth 82A is arranged on the axial surface 82S of the second ratchet member 82. The axial surface 82S of the second ratchet member 82 faces the axial surface 80S of the first ratchet member 80. In the present embodiment, the plurality of second ratchet teeth 82A are arranged on the axial surface 82S of the second ratchet member 82. The axial plane 82S is substantially perpendicular to the axial direction D2. However, the axial plane 82S may be non-perpendicular to the axial D2.

As shown in FIG. 40, the bicycle rear hub assembly 12 includes a spacer 86, a support member 88, a sliding member 90, an additional biasing member 92, and a receiving member 94. However, at least one of the spacer 86, the support member 88, the sliding member 90, the additional urging member 92, and the receiving member 94 may be omitted from the bicycle rear hub assembly 12.

As shown in FIGS. 44 and 45, the spacer 86 is at least partially between at least one first tooth 36T and at least one protrusion 82T in the circumferential direction D1 defined around the center of rotation A1. Provided. In the present embodiment, the spacer 86 is partially provided between the plurality of first teeth 36T and the plurality of protrusions 82T in the circumferential direction D1. However, the spacer 86 may be provided as a whole between the plurality of first teeth 36T and the plurality of protrusions 82T in the circumferential direction D1.

As shown in FIGS. 45-47, the spacer 86 includes at least one intermediate portion 86A provided between at least one first tooth 36T and at least one protrusion 82T. At least one intermediate portion 86A is provided between at least one first tooth 36T and at least one protrusion 82T in the circumferential direction D1. In the present embodiment, the spacer 86 includes a plurality of intermediate portions 86A provided between the plurality of first teeth 36T and the plurality of protrusions 82T in the circumferential direction D1. The spacer 86 includes a plurality of intermediate portions 86A in the present embodiment, but the spacer 86 may include one intermediate portion 86A.

As shown in FIGS. 46 and 47, the spacer 86 includes a connecting portion 86B. The plurality of intermediate portions 86A extend from the connecting portion 86B in the axial direction D2 parallel to the rotation center axis A1. Although the spacer 86 includes the connecting portion 86B in the present embodiment, the connecting portion 86B may be omitted from the spacer 86.

Spacer 86 contains a non-metallic material. In this embodiment, the non-metallic material includes a resin material. Examples of resin materials include synthetic resins. The non-metallic material may include a material other than the resin material in place of the resin material or in addition to the resin material. Although the intermediate portion 86A and the connecting portion 86B are integrally provided with each other as one single member in the present embodiment, at least one of the intermediate portions 86A may be a portion separate from the connecting portion 86B. ..

As shown in FIGS. 44 and 45, the plurality of intermediate portions 86A are provided between the inner peripheral surface 36S of the hub body 36 and the outer peripheral surface 82P of the second ratchet member 82 in the radial direction.

As shown in FIG. 44, the support member 88 is provided between the hub body 36 and the second ratchet member 82 in the axial direction D2. The support member 88 is attached to the second ratchet member 82. The support member 88 is provided on the outer side in the radial direction of the first ratchet member 80. The support member 88 is in contact with the first ratchet member 80. The support member 88 preferably contains a non-metallic material. The support member 88 made of a non-metallic material reduces noise during operation of the bicycle rear hub assembly 12. In this embodiment, the non-metallic material includes a resin material. The non-metallic material may include a material other than the resin material in place of the resin material or in addition to the resin material.

The sliding member 90 is provided between the sprocket support 28 and the second ratchet member 82 in the axial direction D2 parallel to the rotation center axis A1. The second ratchet member 82 is provided between the first ratchet member 80 and the sliding member 90 in the axial direction D2. The sliding member 90 preferably contains a non-metallic material. The sliding member 90 made of a non-metal material reduces noise during operation of the bicycle rear hub assembly 12. In this embodiment, the non-metallic material includes a resin material. The non-metallic material may include a material other than the resin material in place of the resin material or in addition to the resin material.

The sprocket support 28 includes a contact portion 28E for contacting the second ratchet member 82 so as to limit the axial movement of the second ratchet member 82 away from the hub body 36. The contact portion 28E can indirectly contact the second ratchet member 82 via the sliding member 90 in the present embodiment. Alternatively, the contact portion 28E may be in direct contact with the second ratchet member 82. The first ratchet member 80 is arranged on the side opposite to the contact portion 28E of the sprocket support 28 in the axial direction D2 with respect to the second ratchet member 82. The sliding member 90 is provided between the contact portion 28E of the sprocket support 28 and the second ratchet member 82 in the axial direction D2.

As shown in FIG. 44, an additional urging member 92 is provided between the hub body 36 and the second ratchet member 82 in the axial direction D2 so as to urge the second ratchet member 82 toward the sprocket support 28. Be done. In the present embodiment, the additional urging member 92 urges the second ratchet member 82 in the axial direction D2 via the support member 88. The additional urging member 92 is provided on the radial outer side of the urging member 84. The additional urging member 92 is provided on the radial outer side of the plurality of second ratchet teeth 82A in the present embodiment.

The receiving member 94 contains a non-metallic material. The receiving member 94 made of a non-metal material prevents the urging member 84 from being excessively twisted during the operation of the bicycle rear hub assembly 12. In this embodiment, the non-metallic material includes a resin material. The non-metallic material may include a material other than the resin material in place of the resin material or in addition to the resin material. The receiving member 94 includes an axial receiving surface 96 and a radial receiving surface 98. The axial receiving surface 96 is provided between the first ratchet member 80 and the urging member 84 in the axial direction D2. The radial receiving surface 98 extends from the axial receiving surface 96 in the axial direction D2. The radial receiving surface 98 is provided inside the urging member 84 in the radial direction. The axial receiving surface 96 and the radial receiving surface 98 are integrally provided with each other as one single member. However, the axial receiving surface 96 may be a member separate from the radial receiving surface 98.

As shown in FIG. 44, the bicycle rear hub assembly 12 includes a seal structure 100. The seal structure 100 is provided between the sprocket support 28 and the hub body 36. The hub body 36 includes an internal space 102. Each of the sprocket support 28, the urging member 84, the first ratchet member 80, and the second ratchet member 82 is arranged at least partially in the internal space 102 of the hub body 36. The internal space 102 is sealed by the seal structure 100. In the present embodiment, the lubricant is not provided in the internal space 102, but the bicycle rear hub assembly 12 may have a lubricant provided in the internal space 102. Compared to the case where the bicycle rear hub assembly 12 has a lubricant provided in the internal space 102, when the lubricant is not provided, the gaps between the members arranged in the internal space 102 are made smaller. can.

The operation of the bicycle rear hub assembly 12 is described in detail below with reference to FIGS. 44, 48 and 49.

As shown in FIG. 44, the axial direction D2 includes a first axial direction D21 and a second axial direction D22 opposite to the first axial direction D21. The urging force F5 is applied from the urging member 84 to the receiving member 94 in the first axial direction D21. The urging force F5 of the urging member 84 urges the receiving member 94, the first ratchet member 80, the second ratchet member 82, and the sliding member 90 toward the sprocket support 28 in the first axial direction D21. This results in the engagement of the plurality of first ratchet teeth 80A with the plurality of second ratchet teeth 82A.

Furthermore, as shown in FIG. 48, when the pedaling torque T1 is input to the sprocket support 28 in the drive rotation direction D11, the plurality of inner helical spline teeth 80H1 with respect to the sprocket support 28 in the first axial direction D21. Guided by a plurality of outer helical spline teeth 46. This strongly results in the engagement of the plurality of first ratchet teeth 80A with the plurality of second ratchet teeth 82A. In this state, the pedaling torque T1 is transmitted from the sprocket support 28 to the hub body 36 via the first ratchet member 80 and the second ratchet member 82 (FIG. 44).

As shown in FIG. 48, the first ratchet member 80 is engaged from the second ratchet member 82 by the rotational friction force F6 generated between the urging member 84 (FIG. 44) and the first ratchet member 80 during coasting. It contacts the guide portion 28G so as to release the ratchet. As shown in FIG. 49, the inertial torque T2 acts on the hub body 36 in the drive rotation direction D11 during coasting. The inertial torque T2 is transmitted from the hub body 36 (FIG. 44) to the first ratchet member 80 via the second ratchet member 82 (FIG. 44). At this time, the plurality of inner helical spline teeth 80H1 are guided by the plurality of outer helical spline teeth 46 with respect to the sprocket support 28 in the second axial direction D22. As a result, the first ratchet member 80 is moved with respect to the sprocket support 28 in the second axial direction D22 against the urging force F5. Therefore, the first ratchet member 80 moves away from the second ratchet member 82 in the second axial direction D22, and the engagement between the plurality of first ratchet teeth 80A and the plurality of second ratchet teeth 82A is weak. Become. As a result, the second ratchet member 82 can rotate with respect to the first ratchet member 80 in the drive rotation direction D11, and the inertia torque T2 passes through the first ratchet member 80 and the second ratchet member 82 to form the hub body 36. Is prevented from being transmitted to the sprocket support 28. At this time, the plurality of first ratchet teeth 80A slide with the plurality of second ratchet teeth 82A in the circumferential direction D1.

Deformation Example As shown in FIG. 50, in the above embodiment and other modifications, the outer spline tooth 40 has a groove 40G provided between the outer spline driving surface 48 and the outer spline non-driving surface 50 in the circumferential direction D1. It may be included. The groove 40G reduces the weight of the bicycle rear hub assembly 12.

As shown in FIG. 51, in the above embodiment and other modifications, the inner spline tooth 64 includes a groove 64G provided between the inner spline drive surface 66 and the inner spline non-drive surface 68 in the circumferential direction D1. You may. The groove 64G reduces the weight of the bicycle rear sprocket assembly 14.

In the present application, in the above embodiment, at least 10 inner spline teeth are provided directly in the second openings of the second sprockets SP3 and SP4, respectively, whereas at least 10 inner spline teeth are the first of the second sprocket. 2 It may be indirectly provided in the opening. For example, instead of providing at least 10 inner spline teeth directly in the second opening of the second sprocket SP3 and / or the second sprocket SP4, at least one of the second sprockets SP3 and SP4 has at least 10 inner splines. It may be attached to a sprocket support member having teeth. Alternatively, instead of providing at least 10 inner spline teeth directly in the second opening of the second sprocket, at least one second sprocket contains at least 10 inner spline teeth as a single member. It may be formed integrally with the additional sprocket. Since such a second sprocket indirectly includes at least 10 inner sprocket teeth via a sprocket support member and / or an additional sprocket, it also means that the second sprocket is with the sprocket support of the bicycle rear hub assembly. Means include at least 10 medial spline teeth configured to engage.

The bicycle rear sprocket assembly 14 includes two first sprockets SP1 and SP2 in the above embodiment, but the bicycle rear sprocket assembly 14 has only one first sprocket or more first sprocket than two. May include sprockets.

The bicycle rear sprocket assembly 14 includes two second sprockets SP3 and SP4 in the above embodiment, whereas the bicycle rear sprocket assembly 14 contains only one second sprocket or two. May contain more second sprockets.

As shown in FIG. 52, in the sprocket support 28, the total number of at least 10 outer spline teeth 40 may be in the range of 22 to 24. For example, the total number of at least 10 outer spline teeth 40 may be 23. The first outer pitch angle PA11 may be in the range of 13 degrees to 17 degrees. For example, the first outer pitch angle PA11 may be 15 degrees. The second outer pitch angle PA12 may be in the range of 28 degrees to 32 degrees. For example, the second outer pitch angle PA12 may be 30 degrees. The first outer pitch angle PA11 is half of the second outer pitch angle PA12. However, the first outer pitch angle PA11 may be different from half of the second outer pitch angle PA12. The total number of at least 10 outer spline teeth 40 is not limited to the above modifications and ranges. The first outer pitch angle PA11 is not limited to the above modification and range. The second outer pitch angle PA12 is not limited to the above modification and range.

As shown in FIG. 53, in the sprocket support 28, the total of the radial lengths RL11 of the plurality of outer spline drive surfaces 48 may be in the range of 11 mm to 14 mm. The sum of the radial lengths RL11 of the plurality of outer spline drive surfaces 48 may be 12.5 mm. The total length of the additional radial lengths RL12 may be in the range of 26 mm to 30 mm. For example, the total length of the additional radial lengths RL12 may be 28.2 mm. However, the total of the additional radial lengths RL12 is not limited to the above modifications and ranges.

As shown in FIG. 54, in the first torque transmission structure SP1T of the first sprocket SP1, the total number of at least 10 first torque transmission teeth SP1T1 may be in the range of 22 to 24. For example, the total number of at least 10 first torque transmission teeth SP1T1 may be 23. However, the total number of at least 10 first torque transmission teeth SP1T1 is not limited to the above modifications and ranges.

As shown in FIG. 55, in the second torque transmission structure SP2T of the first sprocket SP2, the total number of at least 10 second torque transmission teeth SP2T1 may be in the range of 22 to 24. For example, the total number of at least 10 second torque transmission teeth SP2T1 may be 23. However, the total number of at least 10 second torque transmission teeth SP2T1 is not limited to the above modifications and ranges.

As shown in FIG. 56, in the first sprocket SP2, the total number of at least 10 inner spline teeth 63 of the first sprocket SP2 may be in the range of 22 to 24. For example, the total number of at least 10 inner spline teeth 63 of the first sprocket SP2 may be 23. However, the total number of at least 10 inner spline teeth 63 is not limited to the above modifications and ranges.

As shown in FIG. 57, in the second sprocket SP3, the total number of at least 10 inner spline teeth 64 of the second sprocket SP3 may be in the range of 22 to 24. For example, the total number of at least 10 inner spline teeth 64 of the second sprocket SP3 may be 23. However, the total number of at least 10 inner spline teeth 64 is not limited to the above modifications and ranges.

As shown in FIG. 58, in the second sprocket SP4, the total number of at least 10 inner spline teeth 65 of the second sprocket SP4 may be in the range of 22 to 24. For example, the total number of at least 10 inner spline teeth 65 of the second sprocket SP4 may be 23. However, the total number of at least 10 inner spline teeth 65 is not limited to the above modifications and ranges.

As shown in FIG. 59, in at least 10 inner spline teeth 64 of the second sprocket SP3, the first inner pitch angle PA21 may be in the range of 13 degrees to 17 degrees. For example, the first inner pitch angle PA21 may be 15 degrees. The second inner pitch angle PA22 may be in the range of 28 degrees to 32 degrees. For example, the second inner pitch angle PA22 may be 30 degrees. The first inner pitch angle PA21 may be half of the second inner pitch angle PA22. However, the first inner pitch angle PA21 may be different from half of the second inner pitch angle PA22. The first inner pitch angle PA21 is not limited to the above modification and range. The second inner pitch angle PA22 is not limited to the above modifications and ranges.

As shown in FIG. 60, in the plurality of inner spline teeth 64 of the second sprocket SP3, the total of the radial lengths RL21 of the plurality of inner spline drive surfaces 66 may be in the range of 11 mm to 14 mm. For example, the total number of radial lengths RL21 of the plurality of inner spline drive surfaces 66 may be 12.5 mm. However, the sum of the radial lengths RL21 is not limited to the above modifications and ranges. The total length of the additional radial lengths RL22 may be in the range of 26 mm to 29 mm. For example, the total additional radial length RL22 is 27.6 mm. However, the sum of the additional radial lengths RL22 is not limited to this embodiment and the above range. The plurality of inner spline teeth 63 of the first sprocket SP2 and the plurality of inner spline teeth 65 of the second sprocket SP4 have the same mechanism as those of the plurality of inner spline teeth 64 of the second sprocket SP3.

As shown in FIG. 61, the inner spline teeth 76 of the sprocket support member 37 may have the same mechanism as that of the inner spline teeth 64 of the second sprocket SP3 shown in FIGS. 57, 59 and 60. The total number of at least 10 inner spline teeth 76 of the sprocket support member 37 may be in the range of 22 to 24. For example, the total number of at least 10 inner spline teeth 76 of the sprocket support member 37 may be 23. However, the total number of at least 10 inner spline teeth 76 is not limited to the above modifications and ranges. The mechanism of the plurality of inner spline teeth 64 shown in FIG. 60 is applicable to the plurality of inner spline teeth 76 of the sprocket support member 37.

As shown in FIG. 62, the bicycle rear sprocket assembly 14 may include an additional sprocket SP13. The additional sprocket SP13 is connected to the additional sprocket SP12 by a plurality of connecting members SP13R. The additional sprocket SP13 includes a sprocket body SP13A and at least one sprocket tooth SP13B. The sprocket body SP13A of the additional sprocket SP13 is connected to the sprocket body SP12A of the additional sprocket SP12 by a plurality of connecting members SP13R. At least one sprocket tooth SP13B extends radially outward from the sprocket SP13A. The total number of at least one sprocket tooth SP13B is greater than the total number of at least one sprocket tooth SP12B. Preferably, the total number of teeth of at least one sprocket tooth SP13B is 46 or more. More preferably, the total number of teeth of at least one sprocket tooth SP13B is 50 or more. For example, the total number of teeth of at least one sprocket tooth SP13B is 54.

The tooth contours of the sprockets SP1B to SP13B of the sprockets SP1 to SP13 may have conventional tooth contours and / or narrow-wide tooth contours. Specifically, as a narrow / wide tooth contour, the sprockets SP1B to SP13B of the sprockets SP1 to SP13 also have at least one first tooth having a maximum chain engagement width in the first axial direction and a first tooth in the first axial direction. It may include at least one second tooth, each having a maximum chain engagement width in the second axial direction that is smaller than the maximum chain engagement width. The maximum chain engagement width in the first axial direction and the maximum chain engagement width in the second axial direction are measured along the axial direction D2. The maximum axial chain engagement width is larger than the axial inner link space defined by the pair of inner link plates of the bicycle chain 20 and the axial direction defined by the pair of outer link plates of the bicycle chain 20. Smaller than the outer link space. When the bicycle chain 20 engages with one of the sprockets SP1 to SP13, the pair of outer link plates face each other in the axial direction D2. The maximum second axial chain engagement width is smaller than the axial inner link space defined by the pair of inner link plates of the bicycle chain 20. Therefore, at least one first tooth is configured to engage a pair of outer link plates facing each other in axial D2 when the bicycle chain 20 engages with one of the sprockets SP1 to SP13. , At least one second tooth is configured to engage a pair of inner link plates facing each other in axial D2. Preferably, at least one first tooth and at least one second tooth are alternately arranged on the outer circumference of at least one of the sprockets SP1 to SP13. Preferably, the sprocket teeth SP1B to SP13B of the sprockets SP1 to SP13 each have a plurality of first teeth having the above-mentioned maximum chain engagement width in the first axial direction, and each having the above-mentioned maximum chain engagement width in the second axial direction. Includes a plurality of second teeth. Preferably, the plurality of first teeth and the plurality of second teeth are alternately arranged on the outer periphery of at least one of the sprockets SP1 to SP13. Preferably, the sprocket teeth of the largest sprocket may have such a narrow wide tooth shape. Therefore, the sprocket tooth SP12B of the sprocket SP12 in FIG. 6 or the sprocket tooth SP13B of the sprocket SP13 in FIG. 62 has the first tooth having the above-mentioned maximum chain engagement width in the first axial direction and the above-mentioned maximum chain engagement in the second axial direction. It is preferable to include at least one of at least one second tooth having a width.

In the present application, "provide" and its derivatives are non-restrictive terms that describe the existence of a component and do not preclude the existence of other components not described. This also applies to "have", "contains" and their derivatives.

The terms "-member", "-part", "-element", "-body", and "-structure" can have multiple meanings, such as a single part or multiple parts.

Ordinal numbers such as "first" and "second" are merely terms for identifying the composition and have no other meaning (for example, a specific order). For example, the existence of the "first element" does not imply the existence of the "second element", and the existence of the "second element" does not imply the existence of the "first element". It does not imply to do.

The term "pair" as used herein includes not only the case where the pair of elements has the same shape and structure, but also the case where the pair of elements have different shapes and structures.

Words such as "substantially," "about," and "approximately" that describe the degree can mean a reasonable amount of deviation that does not significantly change the final result. All numbers described herein may be construed to include words such as "substantially," "about," and "approximately."

In view of the above disclosure, it is clear that various modifications and modifications of the present invention are possible. Therefore, the present invention may be carried out by a method different from the specific disclosure contents of the present application without departing from the spirit of the present invention.

10 Bicycle Drive Train, 12 Bicycle Rear Hub Assembly, 14 Bicycle Rear Sprocket Assembly, 16 Bicycle Brake Rotor, 18 Crank Assembly, 20 Bicycle Chain, 22 Crankshaft, 24 Right Crank Arm, 26 Left Crank Arm , 27 front sprocket, 28 sprocket support, 30 hub axle, 32 lock member, 34 brake rotor support, 36 hub body, 37 sprocket support member, 38 spacer, 40 outer sprocket teeth, 64 inner spline teeth, A1 center of rotation

Claims (19)

A sprocket support that is rotatably mounted on the hub axle of a bicycle rear hub assembly.
With at least 10 outer spline teeth configured to engage the bicycle rear sprocket assembly,
With multiple outer helical spline teeth, which are configured to engage with the freewheel mechanism,
Each of the at least 10 outer spline teeth
An outer spline drive surface for receiving the drive rotational force from the bicycle rear sprocket assembly during pedaling,
With an outer spline non-driving surface,
The outer spline drive surface includes a radial outermost edge, a radial innermost edge, and a radial length defined from the radial outermost edge to the radial innermost edge.
The sum of the radial lengths of the outer spline drive surfaces of the at least 10 outer spline teeth is 7 mm or more.
The outer spline crest diameter of the at least 10 outer spline teeth is smaller than the crest diameter of the plurality of outer helical spline teeth.
Sprocket support. The outer spline drive surface is defined between the outer spline drive surface and a first radial line extending from the center of rotation of the bicycle rear hub assembly to the outermost radial edge of the outer spline drive surface. Has a first outer spline surface angle to be
The first outer spline surface angle is 6 degrees or less.
The sprocket support according to claim 1. The outer spline non-driving surface is a dihedral line extending from the rotation center axis of the bicycle rear hub assembly to the radial outermost peripheral edge of the outer spline non-driving surface. Has a dihedral spline surface angle defined between
The dihedral spline surface angle is 6 degrees or less.
The sprocket support according to claim 1 or 2. The axial length of at least one of the at least 10 outer spline teeth is 27 mm or less.
The sprocket support according to any one of claims 1 to 3. The total number of at least 10 outer spline teeth is in the range of 22-24.
The sprocket support according to any one of claims 1 to 4. The at least 10 outer spline teeth have a first outer pitch angle and a second outer pitch angle that is different from the first outer pitch angle.
The sprocket support according to any one of claims 1 to 5. The first outer pitch angle is in the range of 13 degrees to 17 degrees.
The second outer pitch angle is in the range of 28 degrees to 32 degrees.
The sprocket support according to claim 6. The first outer pitch angle is half of the second outer pitch angle.
The sprocket support according to claim 6 or 7. The first outer pitch angle is in the range of 13 degrees to 17 degrees.
The sprocket support according to any one of claims 6 to 8. The sum of the radial lengths on the outer spline drive surface is in the range of 11 mm to 14 mm.
The sprocket support according to any one of claims 1 to 9. At least one of the at least 10 outer spline teeth rotates from the center of rotation to the circumferential center point of the outermost radial end of at least one of the at least 10 outer spline teeth. Symmetrical in the circumferential direction with respect to the radial reference line with respect to the central axis,
The sprocket support according to any one of claims 1 to 10. The outer spline peak diameter is 34 mm or less.
The sprocket support according to any one of claims 1 to 11. The outer spline peak diameter is 33 mm or less.
The sprocket support according to any one of claims 1 to 12. The outer spline peak diameter is 29 mm or more.
The sprocket support according to any one of claims 1 to 13. The outer spline valley diameter of the at least 10 outer spline teeth is 32 mm or less.
The sprocket support according to any one of claims 1 to 14. The outer spline valley diameter is 31 mm or less.
The sprocket support according to claim 15. The outer spline valley diameter is 28 mm or more.
The sprocket support according to claim 15 or 16. Hub axle and
A hub body rotatably mounted on the hub axle around the center of rotation of the bicycle rear hub assembly, and
The sprocket support according to any one of claims 1 to 17,
Rear hub assembly for bicycles. Includes a first ratchet member comprising at least one first ratchet tooth and at least one second ratchet tooth configured to engage the at least one first ratchet tooth to transmit torque. The freewheel mechanism including the second ratchet member is further provided.
The first ratchet member is configured to engage one of the plurality of outer helical spline teeth of the hub body and the sprocket support to transmit torque.
The second ratchet member is configured to engage the other of the plurality of outer helical spline teeth of the hub body and the sprocket support to transmit torque.
At least one of the first ratchet member and the second ratchet member is movable with respect to the hub axle in the axial direction with respect to the center of rotation.
The bicycle rear hub assembly according to claim 18.

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