Shimano Inc.

Yasuhiro Yahata

Koshi Tabe

A chamfered sprocket assembly for facilitating the shifting of a drive chain from a larger sprocket to a smaller sprocket is disclosed. In a preferred embodiment, the chamfered sprocket assembly includes a sprocket having a plurality of chamfered portions on a side facing a smaller sprocket, each chamfered portion located between a pair of toothlike projections located on the rim of the sprocket body. The chamfered portions preferably include a crest which tapers toward a first edge and a second edge of the chamfer portion, respectively. The crest is preferably offset from the center of the chamfer portion toward the driving direction of the sprocket assembly. To further facilitate the shifting of the drive chain, the sprocket preferably includes a rounded shoulder to guide the movement of the drive chain. Finally, the friction between the toothlike projections and the drive chain is reduced by polishing the toothlike projections.

Chamfered sprocket assembly

A ratchet mechanism for a bicycle hub includes a first hub member and a second hub member, wherein the first hub member and the second hub member are rotatable relative to each other. A pawl is supported by the first hub member, a ratchet tooth is supported by the second hub member, and a biasing mechanism is provided for biasing the pawl toward the ratchet tooth. A pawl control mechanism is responsive to relative rotation of the first hub member and the second hub member for allowing the pawl to contact the ratchet tooth when the first hub member and the second hub member rotate relative to each other in one direction and for preventing the pawl from contacting the ratchet tooth when the first hub member and the second hub member rotate relative to each other in an opposite direction.

Pawl noise dampening mechanism for a bicycle freewheel

Freewheel body for a freehub

A bicycle hub apparatus is constructed of a hub shell and a plurality of spoke attachment parts disposed circumferentially about the hub shell at opposite end portions of the hub shell, wherein each spoke attachment part includes a first through hole and a second through hole. In each spoke attachment part, the first through hole is located at a different radial position relative to a central hub axis of the hub shell when compared to the second through hole.

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Osaka, Japan

Yasuhiro Yahata