Bicycle rear hub assembly
A bicycle rear hub assembly comprises a hub axle, a hub body, and a sprocket support body. The hub axle includes an axle through-bore that has a minimum inner diameter equal to or larger than 13 mm. The hub body is rotatably mounted on the hub axle about a rotational center axis of the bicycle rear hub assembly. The sprocket support body is rotatably mounted on the hub axle about the rotational center axis.
1. A bicycle rear hub assembly comprising:
a hub axle including an axle through-bore that has a minimum inner diameter equal to or larger than 13 mm;
a hub body rotatably mounted on the hub axle about a rotational center axis of the bicycle rear hub assembly, the hub body being rotatable relative to the hub axle; and
a sprocket support body rotatably mounted on the hub axle about the rotational center axis, wherein
the sprocket support body includes at least one external spline tooth configured to engage with a bicycle rear sprocket assembly,
the at least one external spline tooth includes a plurality of external spline teeth including a plurality of external-spline driving surfaces to receive a driving rotational force from the bicycle rear sprocket assembly during pedaling,
the plurality of external-spline driving surfaces each includes
a radially outermost edge,
a radially innermost edge, and
a radial length defined from the radially outermost edge to the radially innermost edge, and
a total of the radial lengths of the plurality of external-spline driving surfaces is equal to or larger than 7 mm.
2. The bicycle rear hub assembly according to claim 1 , wherein the minimum inner diameter of the axle through-bore is equal to or larger than 14 mm.
3. The bicycle rear hub assembly according to claim 1 , wherein
the minimum inner diameter of the axle through-bore is equal to or smaller than 21 mm.
4. The bicycle rear hub assembly according to claim 1 , wherein
the hub axle has a maximum outer diameter that is equal to or larger than 17 mm.
5. The bicycle rear hub assembly according to claim 4 , wherein
the maximum outer diameter of the hub axle is equal to or larger than 20 mm.
6. The bicycle rear hub assembly according to claim 4 , wherein
the maximum outer diameter of the hub axle is equal to or smaller than 23 mm.
7. The bicycle rear hub assembly according to claim 1 , wherein
the sprocket support body includes at least ten external spline teeth configured to engage with the bicycle rear sprocket assembly, each of the at least ten external spline teeth having the external-spline driving surface and an external-spline non-driving surface.
8. The bicycle rear hub assembly according to claim 7 , wherein
a total number of the at least ten external spline teeth is equal to or larger than 20.
9. The bicycle rear hub assembly according to claim 7 , wherein
a total number of the at least ten external spline teeth is equal to or larger than 25.
10. The bicycle rear hub assembly according to claim 7 , wherein
a total number of the at least ten external spline teeth is equal to or larger than 28.
11. The bicycle rear hub assembly according to claim 7 , wherein
at least one of the at least ten external spline teeth has an axial spline-tooth length that is equal to or smaller than 27 mm.
12. The bicycle rear hub assembly according to claim 11 , wherein
the axial spline-tooth length is equal to or larger than 22 mm.
13. The bicycle rear hub assembly according to claim 7 , wherein
the at least ten external spline teeth have a first external pitch angle and a second external pitch angle different from the first external pitch angle.
14. The bicycle rear hub assembly according to claim 7 , wherein
at least two external spline teeth of the at least ten external spline teeth are circumferentially arranged at a first external pitch angle with respect to the rotational center axis, and
the first external pitch angle ranging from 5 degrees to 36 degrees.
15. The bicycle rear hub assembly according to claim 14 , wherein
the first external pitch angle ranges from 10 degrees to 20 degrees.
16. The bicycle rear hub assembly according to claim 15 , wherein
the first external pitch angle is equal to or smaller than 15 degrees.
17. The bicycle rear hub assembly according to claim 7 , wherein
at least one of the at least ten external spline teeth is circumferentially symmetric with respect to a reference line extending from the rotational center axis to a circumferential center point of a radially outermost end of the at least one of the at least ten external spline teeth in a radial direction with respect to the rotational center axis.
18. The bicycle rear hub assembly according to claim 17 , wherein
at least one surface of the plurality of external-spline driving surfaces has a first external-spline-surface angle defined between the external-spline driving surface and a first radial line extending from a rotational center axis of the bicycle rear hub assembly to the radially outermost edge of the external-spline driving surface, and
the first external-spline-surface angle is equal to or smaller than 6 degrees.
19. The bicycle rear hub assembly according to claim 18 , wherein
at least one of the external-spline non-driving surfaces has a second external-spline-surface angle defined between the external-spline non-driving surface and a second radial line extending from the rotational center axis of the bicycle rear hub assembly to a radially outermost edge of the external-spline non-driving surface, and
the second external-spline-surface angle is equal to or smaller than 6 degrees.
20. The bicycle rear hub assembly according to claim 7 , wherein
at least one of the at least ten external spline teeth has an axial spline-tooth length that is equal to or smaller than 27 mm.
21. The bicycle rear hub assembly according to claim 7 , wherein
a total number of the at least ten external spline teeth ranges from 22 to 24.
22. The bicycle rear hub assembly according to claim 13 , wherein
the first external pitch angle ranges from 13 degrees to 17 degrees, and
the second external pitch angle ranges from 28 degrees to 32 degrees.
23. The bicycle rear hub assembly according to claim 13 , wherein
the first external pitch angle is half of the second external pitch angle.
24. The bicycle rear hub assembly according to claim 14 , wherein
the first external pitch angle ranges from 13 degrees to 17 degrees.
25. The bicycle rear hub assembly according to claim 1 , wherein
the at least one external spline tooth has an external-spline major diameter that is equal to or smaller than 34 mm.
26. The bicycle rear hub assembly according to claim 25 , wherein the external-spline major diameter is equal to or smaller than 33 mm.
27. The bicycle rear hub assembly according to claim 25 , wherein the external-spline major diameter is equal to or larger than 29 mm.
28. The bicycle rear hub assembly according to claim 1 , wherein
the at least one external spline tooth has an external-spline minor diameter that is equal to or smaller than 32 mm.
29. The bicycle rear hub assembly according to claim 28 , wherein
the external-spline minor diameter is equal to or smaller than 31 mm.
30. The bicycle rear hub assembly according to claim 28 , wherein
the external-spline minor diameter is equal to or larger than 28 mm.
31. The bicycle rear hub assembly according to claim 1 , wherein
the total of the radial lengths is equal to or larger than 10 mm.
32. The bicycle rear hub assembly according to claim 1 , wherein
the total of the radial lengths is equal to or larger than 15 mm.
33. The bicycle rear hub assembly according to claim 1 , wherein
the total of the radial lengths is equal to or smaller than 36 mm.
34. The bicycle rear hub assembly according to claim 1 , wherein
the hub body includes:
a first spoke-mounting portion having a first axially outermost part;
a second spoke-mounting portion having a second axially outermost part; and
a first axial length defined between the first axially outermost part of the first spoke-mounting portion and the second axially outermost part of the second spoke-mounting portion in an axial direction with respect to the rotational center axis of the bicycle rear sprocket assembly, the first axial length being equal to or larger than 55 mm.
35. The bicycle rear hub assembly according to claim 34 , wherein
the first axial length is equal to or larger than 60 mm.
36. The bicycle rear hub assembly according to claim 34 wherein
the first axial length is equal to or larger than 65 mm.
37. The bicycle rear hub assembly according to claim 1 , wherein
the hub axle includes:
a first axial frame abutment surface configured to abut against a first part of a bicycle frame in an axial direction with respect to the rotational center axis of the bicycle rear sprocket assembly in a state where the bicycle rear hub assembly is mounted to the bicycle frame;
a second axial frame abutment surface configured to abut against a second part of the bicycle frame in the axial direction in the state where the bicycle rear hub assembly is mounted to the bicycle frame; and
a second axial length defined between the first axial frame abutment surface and the second axial frame abutment surface in the axial direction, the second axial length being equal to or larger than 140 mm.
38. The bicycle rear hub assembly according to claim 37 , wherein
the second axial length is equal to or larger than 145 mm.
39. The bicycle rear hub assembly according to claim 37 , wherein
the second axial length is equal to or larger than 147 mm.
40. A bicycle rear hub assembly comprising:
a hub axle including an axle through-bore that has a minimum inner diameter equal to or larger than 13 mm;
a hub body rotatably mounted on the hub axle about a rotational center axis of the bicycle rear hub assembly;
a sprocket support body rotatably mounted on the hub axle about the rotational center axis; and
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 hub body and the sprocket support body in a torque transmitting manner,
the second ratchet member is configured to engage with the other of the 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 hub axle in an axial direction with respect to the rotational center axis.
41. The bicycle rear hub assembly according to claim 40 , wherein
the at least one first ratchet tooth is disposed on an axial facing surface of the first ratchet member,
the at least one second ratchet tooth is disposed on an axial facing surface of the second ratchet member, and
the axial facing surface of the second ratchet member faces the axial facing surface of the first ratchet member.
42. The bicycle rear hub assembly according to claim 40 , wherein
the sprocket support body has an outer peripheral surface having a first helical spline, and
the first ratchet member is configured to engage with the sprocket support body in a torque transmitting manner and includes a second helical spline mating with the first helical spline.
43. The bicycle rear hub assembly according to claim 42 , wherein
the outer peripheral surface of the sprocket support body has a guiding portion configured to guide the first ratchet member toward the hub body during coasting.
44. The bicycle rear hub assembly according to claim 43 , wherein
the guiding portion guides the first ratchet member toward the hub body to release a meshing engagement between the at least one first ratchet tooth and the at least one second ratchet tooth during coasting.
45. The bicycle rear hub assembly according to claim 43 , wherein
the guiding portion extends in at least a circumferential direction with respect to the sprocket support body.
46. The bicycle rear hub assembly according to claim 43 , wherein
the guiding portion is arranged to define an obtuse angle with the first helical spline.
47. The bicycle rear hub assembly according to claim 40 , wherein
each of the first ratchet member and the second ratchet member has an annular shape.
48. A bicycle rear hub assembly comprising:
a hub axle including an axle through-bore that has a minimum inner diameter equal to or larger than 13 mm;
a hub body rotatably mounted on the hub axle about a rotational center axis of the bicycle rear hub assembly;
a sprocket support body rotatably mounted on the hub axle about the rotational center axis; and
a brake-rotor support body including at least one additional external spline tooth configured to engage with a bicycle brake rotor, wherein
the at least one additional external spline tooth has an additional external-spline major diameter that is larger than the external-spline major diameter.
49. A bicycle rear hub assembly comprising:
a hub axle;
a hub body rotatably mounted on the hub axle about a rotational center axis of the bicycle rear hub assembly; and
a sprocket support body rotatably mounted on the hub axle about the rotational center axis, the sprocket support body including at least ten external spline teeth configured to engage with a bicycle rear sprocket assembly, each of the at least ten external spline teeth having an external-spline driving surface and an external-spline non-driving surface, at least one of the at least ten external spline teeth being circumferentially symmetric with respect to a reference line extending from the rotational center axis to a circumferential center point of a radially outermost end of the at least one of the at least ten external spline teeth in a radial direction with respect to the rotational center axis, wherein
the external-spline driving surfaces includes
a radially outermost edge,
a radially innermost edge, and
a radial length defined from the radially outermost edge to the radially innermost edge, and
a total of the radial lengths of the external-spline driving surfaces is equal to or larger than 7 mm.
50. The bicycle rear hub assembly according to claim 49 , wherein
a total number of the at least ten external spline teeth is equal to or larger than 28.
51. The bicycle rear hub assembly according to claim 49 , wherein
at least one of the external-spline driving surfaces has a first external-spline-surface angle defined between the external-spline driving surface and a first radial line extending from a rotational center axis of the bicycle rear hub assembly to the radially outermost edge of the external-spline driving surface, and
the first external-spline-surface angle is equal to or smaller than 6 degrees.
52. The bicycle rear hub assembly according to claim 51 , wherein
at least one of the external-spline non-driving surfaces has a second external-spline-surface angle defined between the external-spline non-driving surface and a second radial line extending from the rotational center axis of the bicycle rear hub assembly to a radially outermost edge of the external-spline non-driving surface, and
the second external-spline-surface angle is equal to or smaller than 6 degrees.
53. The bicycle rear hub assembly according to claim 49 , wherein
at least one of the at least ten external spline teeth has an axial spline-tooth length that is equal to or smaller than 27 mm.
54. The bicycle rear hub assembly according to claim 49 , wherein
a total number of the at least ten external spline teeth ranges from 22 to 24.
55. The bicycle rear hub assembly according to claim 23 , wherein
the total of the radial lengths of the plurality of external-spline driving surfaces ranges from 11 mm to 14 mm.