A cogset with a plurality of sprockets has a subset of the sprockets connected together in a monolithic subset that is mounted directly in engagement with a coupling profile on the radially peripheral surface of a sprocket in the monolithic subset. The direct shape coupling between the sprocket of the monolithic subset and the sprocket-carrying body makes it possible to have very high solidity and rigidity of coupling to ensure the maximum precision of actuation of the gearshift that uses the sub-assembly.

A cogset with a plurality of sprockets has a subset of the sprockets connected together in a monolithic subset that is mounted directly in engagement with a coupling profile on the radially peripheral surface of a sprocket in the monolithic subset. The direct shape coupling between the sprocket of the monolithic subset and the sprocket-carrying body makes it possible to have very high solidity and rigidity of coupling to ensure the maximum precision of actuation of the gearshift that uses the sub-assembly.

A bicycle sprocket assembly comprises a first sprocket and a second sprocket. The first sprocket includes a plurality of first sprocket teeth, a first sprocket inward surface, a first sprocket outward surface, and an axial space. The second sprocket includes a plurality of second sprocket teeth, a second sprocket inward surface, and a second sprocket outward surface. The axial space is defined between the first sprocket outward surface and an axially inward outer link plate in the axial direction while the second sprocket outward surface contacts an axially outward inner link plate in an engagement state where the one of the plurality of the second sprocket teeth is positioned between an axially inward inner link plate and the axially outward inner link plate in the axial direction. The axial space is larger than mm and equal to or smaller than 0.15 mm.

A bicycle sprocket assembly comprises a first sprocket and a second sprocket. The first sprocket includes a plurality of first sprocket teeth, a first sprocket inward surface, a first sprocket outward surface, and an axial space. The second sprocket includes a plurality of second sprocket teeth, a second sprocket inward surface, and a second sprocket outward surface. The axial space is defined between the first sprocket outward surface and an axially inward outer link plate in the axial direction while the second sprocket outward surface contacts an axially outward inner link plate in an engagement state where the one of the plurality of the second sprocket teeth is positioned between an axially inward inner link plate and the axially outward inner link plate in the axial direction. The axial space is larger than mm and equal to or smaller than 0.15 mm.

Provided are a rotation assist tool 10 attached to a base side of a rotary shaft 12 having an output unit 11 on a front side thereof and a assist-attached rotation tool 31 including the rotation assist tool 10. The rotation assist tool 10 has a first rotating body 13; a second rotating body 14 that is held by the first rotating body 13 to be rotatable in forward and reverse directions; and at least one elastically deformable body 22 that is elastically deformed as the first rotating body 13 and the second rotating body 14 rotate relative to each other, and transmits rotation between the first rotating body 13 and the second rotating body 14, wherein the base side of the rotary shaft 12 is fixed to the first rotating body 13.

A sub-assembly is presented, for a bicycle rear wheel, formed by a sprocket-carrying body and a cogset mounted coaxially on the sprocket-carrying body through shape engagement, is sized such that a good compromise is obtained between the ability to house a relatively large number of sprockets and the structural solidity of the sub-assembly.

A sub-assembly is presented, for a bicycle rear wheel, formed by a sprocket-carrying body and a cogset mounted coaxially on the sprocket-carrying body through shape engagement, is sized such that a good compromise is obtained between the ability to house a relatively large number of sprockets and the structural solidity of the sub-assembly.

A bicycle sprocket having a rotational center axis, the bicycle sprocket comprises a sprocket body, a chain engagement structure, and a shifting facilitation projection. The chain engagement structure is arranged on a radially outer periphery of the sprocket body. The chain engagement structure includes a plurality of chain-driving teeth to engage with a bicycle chain to transmit a rotational driving force to the bicycle chain. The shifting facilitation projection is to facilitate an upshifting operation of the bicycle chain and to facilitate a downshifting operation of the bicycle chain.

A bicycle sprocket having a rotational center axis, the bicycle sprocket comprises a sprocket body, a chain engagement structure, and a shifting facilitation projection. The chain engagement structure is arranged on a radially outer periphery of the sprocket body. The chain engagement structure includes a plurality of chain-driving teeth to engage with a bicycle chain to transmit a rotational driving force to the bicycle chain. The shifting facilitation projection is to facilitate an upshifting operation of the bicycle chain and to facilitate a downshifting operation of the bicycle chain.

A bicycle chain ring, including an inner edge fully circumscribing both an opening and an axis of rotation; an inner surface extending between the inner edge and an outer edge where a plurality of chain ring teeth emanate; and a plurality of ramps disposed about the inner surface, wherein at least one of the plurality of ramps has a lifting surface configured to concurrently engage at least one link of a bicycle chain at two or more distinct pivot points along the length of the chain link to initiate stable lift of the bicycle chain without assistance from any of the plurality of chain ring teeth; wherein the lifting surface has a first end proximate the inner edge and a second end proximate the outer edge.