Bicycle rear hub assembly and sprocket support body

Abstract

A bicycle rear wheel assembly includes a hub axle, a hub body, and a sprocket support body. The hub axle includes a through-hole having a minimum inner diameter equal to or greater than 13 mm. The hub body is rotatably mounted on the hub axle about a rotational central axis of the bicycle rear wheel assembly. The sprocket support body is rotatably mounted on the hub axle about the rotational central axis.

Claims

1. A sprocket support body rotatably mounted on a hub axle of a bicycle rear wheel assembly, the sprocket support body comprising: at least ten external splined teeth configured to engage with a bicycle rear sprocket assembly, the bicycle rear sprocket assembly including a sprocket support member, a plurality of sprockets attached to the sprocket support member, each of the at least ten external splined teeth having an external splined driving surface and an external splined non-driving surface, each of the at least ten external splined teeth having an external splined driving surface for receiving a driven rotational force from the bicycle rear sprocket assembly during pedaling, the external splined driving surface including a radially outermost edge, a radially innermost edge, and a radial length defined from the radially outermost edge to the radially innermost edge, and the sum of the radial lengths of the external splined driving surfaces of the at least ten external splined teeth being equal to or greater than 7 mm. The external spline drive surface has a first external spline surface angle defined between the external spline drive surface and a first radial line extending from a rotational center axis of the bicycle rear wheel hub assembly to the outermost radial edge of the external spline drive surface. The first external spline surface angle is equal to or greater than 0 degrees and equal to or less than 6 degrees. The sprocket support body has a first axial end and a second axial end. Relative to the rotational center axis, the second axial end is opposite to the first axial end in an axial direction. The second axial end is closer to the wheel hub body in the axial direction than the first axial end. The at least ten external spline teeth are configured to engage with the sprocket support member of the bicycle rear sprocket assembly between the first axial end and the second axial end of the sprocket support body.

2. The sprocket support body of claim 1, wherein the at least ten external spline teeth have an external spline tip diameter, the external spline tip diameter being uniform between the first axial end and the second axial end of the sprocket support body.

3. The sprocket support body of claim 1, wherein the external spline non-drive surface has a second external spline surface angle defined between the external spline non-drive surface and a second radial line, the second radial line extending from the rotation center axis to one of the radial outermost edges of the external spline non-drive surface, and the second external spline surface angle is equal to or less than 6 degrees.

4. The sprocket support body of claim 1, wherein at least one of the at least ten external spline teeth has an axial spline tooth length equal to or less than 27 mm.

5. The sprocket support body of claim 1, wherein the total number of one of the at least ten external spline teeth ranges from 22 to 24.

6. The sprocket support body of claim 1, wherein the total number of one of the at least ten external spline teeth is equal to 23.

7. The sprocket support body of claim 1, wherein the at least ten external splines have a first external pitch angle and a second external pitch angle different from the first external pitch angle.

8. The sprocket support body of claim 7, wherein the first outer pitch angle ranges from 13 degrees to 17 degrees, and the second outer pitch angle ranges from 28 degrees to 32 degrees.

9. The sprocket support body of claim 7, wherein the first outer pitch angle is half of the second outer pitch angle.

10. The sprocket support body of claim 7, wherein the first outer pitch angle ranges from 13 degrees to 17 degrees.

11. The sprocket support body of claim 1, wherein the sum of the radial lengths of the external spline drive surfaces ranges from 11 mm to 14 mm.

12. The sprocket support body of claim 1, wherein at least one of the at least ten external splines is circumferentially symmetrical with respect to a reference line, the reference line extending radially from the rotation axis to a circumferential center point at the radially outermost end of one of the at least ten external splines.

13. The sprocket support body of claim 1, wherein the at least ten external spline teeth have an external spline tip diameter equal to or less than 34 mm.

14. The sprocket support body as claimed in claim 13, wherein the external spline top diameter is equal to or less than 33 mm.

15. The sprocket support body of claim 13, wherein the external spline top diameter is equal to or greater than 29 mm.

16. The sprocket support body of claim 1, wherein the at least ten external spline teeth have an external spline base diameter equal to or less than 32 mm.

17. The sprocket support body of claim 16, wherein the outer spline base diameter is equal to or less than 31 mm.

18. The sprocket support body of claim 16, wherein the outer spline base diameter is equal to or greater than 28 mm.

19. A bicycle rear wheel hub assembly comprising: a hub axle; a hub body rotatably mounted on the hub axle about a rotational central axis of the bicycle rear wheel hub assembly; and the sprocket support body as claimed in claim 1.

20. The bicycle rear wheel assembly of claim 19, further comprising a freewheel structure including a first ratchet member including at least one first ratchet tooth, and a second ratchet member including at least one second ratchet tooth configured to engage with the at least one first ratchet tooth in a torque-transmitting manner, wherein the first ratchet member is configured to engage with one of the wheel hub body and the sprocket support body in a torque-transmitting manner, and the second ratchet member is configured to engage with the other of the wheel hub body and the sprocket support body in a torque-transmitting manner, and at least one of the first ratchet member and the second ratchet member is movable relative to the wheel hub axis in the axial direction relative to the rotation center axis.

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