A bicycle drive includes a multi-sprocket arrangement for rotatable mounting on a rear-wheel axle an engagement with a bicycle chain having inner link plate pairs and chain outer link plate pairs. The multi-sprocket arrangement includes a sprocket having, between an axial inner side and an oppositely situated axial outer side, a flat sprocket body and a plurality of teeth formed on a circumference of the sprocket. The plurality of teeth include at least one tooth of a first tooth group, the axial width of which is dimensioned to be greater than a chain inner link plate spacing and smaller than a chain outer link plate spacing, and a second tooth group, the axial width of which are dimensioned to be smaller than the chain inner link plate spacing.

A bicycle drive unit includes a housing, a crankshaft and a propulsion assist motor. The housing is configured to be coupled to a frame of a bicycle. The housing includes first and second portions. The crankshaft is provided to the first portion of the housing. The propulsion assist motor is provided to the second portion of the housing. The propulsion assist has a rotational axis extending in a direction intersecting with a direction in which the crankshaft extends. A maximum dimension of the first portion in the direction in which the crankshaft extends is less than or equal to 100 mm. A maximum output torque of the propulsion assist motor is greater than or equal to 10 Nm and less than or equal to 80 Nm.

Chain-rings set for bicycle including a first chain-ring and a second chain-ring, this latter formed by segments, which includes displacement means with axial component of the segments with respect to the first chain-ring such that they can be moved a the chain free zone ZLC and shift the chain among chain-rings, where the axial displacement means are formed by guiding means configured for guiding the segments such that the relative movement of the teeth of the segments with respect to the small chain-ring in its displacement from a first disengagement configuration to a second engagement configuration has a tangential component opposite to the forward direction.

Methods and apparatus for a composite bicycle front sprocket are disclosed herein. One embodiment discloses a composite bicycle front sprocket assembly having an outer assembly of a first material. The bicycle front sprocket assembly also has a center assembly of a second material. The center assembly is disposed at least partially within the outer assembly. The center assembly is irremovably coupled with the outer assembly. The center assembly is irremovably coupled with the outer assembly without an external fastening device to irremovably couple the center assembly with the outer assembly.

A crank assembly comprises a crank arm, a front sprocket unit, and a plurality of chain-drop control protrusions. The plurality of chain-drop control protrusions is configured to inhibit a drive chain from getting into a space provided radially inwardly from the plurality of chain-drop control protrusions and between the crank arm and the front sprocket unit in an axial direction. The plurality of chain-drop control protrusions is configured to be provided to at least one of an axially inwardly facing crank-surface of the crank arm and an axially outwardly facing sprocket-surface of the front sprocket unit. The plurality of chain-drop control protrusions is spaced apart from each other in a circumferential direction with respect to the rotational center axis.

A crank assembly comprises a crank arm, a front sprocket unit, and at least one chain-drop control protrusion. The at least one chain-drop control protrusion is configured to inhibit a drive chain from getting into a space provided radially inwardly from the at least one control protrusion and between the crank arm and the front sprocket unit in the axial direction. The at least one chain-drop control protrusion is configured to be provided to at least one of an axially inwardly facing crank-surface of the crank arm and an axially outwardly facing sprocket-surface of the front sprocket unit. The at least one chain-drop control protrusion has a through bore.

A chainring assembly includes a chainring carrier adapted to be coupled to a crank arm. The chainring carrier is rotatable about a rotation axis, and includes an outer periphery having carrier threads. A chainring structure includes an inner periphery having chainring threads and an outer periphery comprising a plurality of teeth. The inner periphery of the chainring structure is threadably engaged with the outer periphery of the chainring carrier. In one embodiment, a power meter device includes a body having a torque input section and a torque output section, with the torque output section including an outer periphery having threads adapted to be coupled to a chainring structure.

An assembly for minimizing the disengagement of a chain from a chain ring is disclosed. The assembly includes an inboard leg and an outboard leg. The outboard leg is configured to slide vertically relative to the inboard leg. A fastener passes through the inboard leg and outboard leg and defines the upper and lower limit of sliding of the outboard leg.

A system and method for simple transmission of a multi-speed bicycle is provided. A bicycle can have a transmission that can be toggled by a kickback shifting mechanism. A rear wheel hub can support a freewheel having a high speed gear sprocket and a low speed gear sprocket with dedicated chains to create dedicated gear-shifting. Rotating the pedal shaft in the non-drive direction approximately one-quarter rotation can toggle the transmission between the first gear ratio and the second gear ratio with a shifting surface that alternately allows driving engagement of the high speed gear sprocket with the rear wheel driver.

A chainring is disclosed. The chainring includes a plurality of teeth about the outer perimeter of the chainring; and a chain retention feature at a root of one or more of the plurality of teeth and traversing at least a portion of a circumference of the chainring, the chain retention feature to align with at least a portion of a roller chain and assist in a retention of the roller chain on the chainring.