A bicycle sprocket arrangement comprises an internal spline configured to be engaged with an external spline of a sprocket support body of a bicycle hub assembly. The internal spline includes a plurality of internal-spline driving surfaces configured to transmit a rotational driving force between the bicycle sprocket arrangement and the bicycle hub assembly in a circumferential direction. The plurality of internal-spline driving surfaces includes at least four first internal-spline driving surfaces and at least one second internal-spline driving surface. The at least four first internal-spline driving surfaces are respectively arranged on at least four of nine first internal-spline driving positions equally arranged in the circumferential direction about a rotational center axis at a first internal-spline pitch angle which is equal to 40 degrees. The at least one second internal-spline driving surface is offset from the nine first internal-spline driving positions in the circumferential direction about the rotational center axis.

A bicycle sprocket arrangement comprises an internal spline configured to be engaged with an external spline of a sprocket support body of a bicycle hub assembly. The internal spline includes a plurality of internal-spline driving surfaces configured to transmit a rotational driving force between the bicycle sprocket arrangement and the bicycle hub assembly in a circumferential direction. The plurality of internal-spline driving surfaces includes at least four first internal-spline driving surfaces and at least one second internal-spline driving surface. The at least four first internal-spline driving surfaces are respectively arranged on at least four of nine first internal-spline driving positions equally arranged in the circumferential direction about a rotational center axis at a first internal-spline pitch angle which is equal to 40 degrees. The at least one second internal-spline driving surface is offset from the nine first internal-spline driving positions in the circumferential direction about the rotational center axis.

A bicycle rear sprocket assembly comprises a first sprocket. The first sprocket includes a first sprocket body, a plurality of first sprocket teeth, a bearing unit mounting section, and a first torque-transmitting structure. The plurality of first sprocket teeth extend radially outwardly from a first radially outer periphery of the first sprocket body with respect to a rotational center axis. The bearing unit mounting section is at least partly provided to a first radially inner periphery of the first sprocket body. The first torque-transmitting structure is configured to transmit pedaling torque to a second sprocket separately disposed adjacent to the first sprocket without another sprocket between the first sprocket and the second sprocket. The first torque-transmitting structure is provided to a first bicycle inbound facing surface and is a separate member from the second sprocket.

A bicycle rear sprocket assembly comprises a first sprocket. The first sprocket includes a first sprocket body, a plurality of first sprocket teeth, a bearing unit mounting section, and a first torque-transmitting structure. The plurality of first sprocket teeth extend radially outwardly from a first radially outer periphery of the first sprocket body with respect to a rotational center axis. The bearing unit mounting section is at least partly provided to a first radially inner periphery of the first sprocket body. The first torque-transmitting structure is configured to transmit pedaling torque to a second sprocket separately disposed adjacent to the first sprocket without another sprocket between the first sprocket and the second sprocket. The first torque-transmitting structure is provided to a first bicycle inbound facing surface and is a separate member from the second sprocket.

A cinch direct mount 2× ring system is disclosed. One embodiment discloses a chainring assembly having a drive side crank arm with a chainring assembly interface including a plurality of splines, a circumference, and an axial length. The chainring assembly includes a first chainring having a first outer diameter and a first center assembly shape. The chainring assembly includes a second chainring having a second outer diameter and a second center assembly shape, the second outer diameter being different than the first outer diameter. The chainring assembly also includes a fastener to couple the first chainring and the second chainring with the chainring assembly interface, such that at least one of the first center assembly shape or the second center assembly shape engages with the plurality of splines.

A chain for a bicycle, a sprocket cassette, a chainring, a crankset, a chain drive system, and a bicycle are provided. The chain comprises a plurality of interleaved link elements, each link element being pivotably attached to at least one other link element and comprising at least two teeth. A flank of each tooth is adapted to engage with a flank of a sprocket tooth. The sprocket cassette comprises one or more sprockets, each comprising a plurality of sprocket teeth, wherein each sprocket tooth has a flank with a profile corresponding to a profile of at least part of a tooth of each of the plurality of link elements. The chainring comprises a plurality of sprocket drive teeth having a profile corresponding to the profile of at least one of the teeth of each of the plurality of link elements.

A chain for a bicycle, a sprocket cassette, a chainring, a crankset, a chain drive system, and a bicycle are provided. The chain comprises a plurality of interleaved link elements, each link element being pivotably attached to at least one other link element and comprising at least two teeth. A flank of each tooth is adapted to engage with a flank of a sprocket tooth. The sprocket cassette comprises one or more sprockets, each comprising a plurality of sprocket teeth, wherein each sprocket tooth has a flank with a profile corresponding to a profile of at least part of a tooth of each of the plurality of link elements. The chainring comprises a plurality of sprocket drive teeth having a profile corresponding to the profile of at least one of the teeth of each of the plurality of link elements.

A chain and an inner link plate for a bicycle chain having chain rollers is provided. A protrusion of the inner link plate in relation to the respectively assigned chain roller in a front lower longitudinal end region of an inner link plate outer periphery is reduced, in comparison to the protrusion in a front upper longitudinal end region and/or in a rear lower longitudinal end region of the inner link plate outer periphery.

A bicycle rear wheel adapter has an annular body that abuts a sprocket-carrying body that extends in an axially outer direction and receives sprockets in radially peripheral positions. A coupling element on the annular body couples with the sprocket-carrying body so the adapter rotates as a unit with the sprocket-carrying body, and a sprocket-receiving seat on the annular body couples with a sprocket so the adapter rotates as a unit with the sprocket. The adapter is suitable for cogsets with small sprockets grouped in a monolithic grouping.

A bicycle rear wheel adapter has an annular body that abuts a sprocket-carrying body that extends in an axially outer direction and receives sprockets in radially peripheral positions. A coupling element on the annular body couples with the sprocket-carrying body so the adapter rotates as a unit with the sprocket-carrying body, and a sprocket-receiving seat on the annular body couples with a sprocket so the adapter rotates as a unit with the sprocket. The adapter is suitable for cogsets with small sprockets grouped in a monolithic grouping.