A bicycle sprocket comprises sprocket teeth. The sprocket teeth include at least one first tooth and at least one second tooth. The at least one first tooth has a first radial-tooth height. The at least one first tooth has an axial center plane in an axial direction parallel to the rotational center axis. The at least one second tooth is adjacent to the first tooth and disposed on a downstream side in a rotational driving direction of the bicycle sprocket. The at least one second tooth has a second radial-tooth height. The first radial-tooth height is greater than the second radial-tooth height. The at least one first tooth includes a tooth tip having an axial center plane in the axial direction. The axial center plane of the tooth tip is offset from the axial center plane of the first tooth in an axial direction.

Provided is a sprocket having a body formed by a powder metallurgy process with a predetermined density and vibration energy absorbing properties, and teeth with a greater density than the density of the body, and a method of making the same. The sprocket minimizes mechanical vibration during a chain-to-sprocket tooth contact. The teeth of the sprocket have a higher density than the body of the sprocket.

Provided is a sprocket which suppresses generation of order sounds corresponding to cycles and prevents increase in tension fluctuations, noise, and vibrations caused by resonance while alleviating the influence of the tension fluctuations corresponding to load torque fluctuations and suppressing noise and vibrations. A plurality of teeth formed to engage with a chain are arranged to form a phase fluctuation pattern of a waveform having a phase which fluctuates between positive and negative sides, and the phase fluctuation pattern is set to have parts having different wavelengths.

Retainer rings for locking in an N-sided shaft to restrict axial movement of components sandwiched between them. The retainer rings have inner edges bounding a central bore. The inner edges are defined by a series of N arcs whose distance from the bore's center decreases gradually along the inner edge from a first end to a second end of each arc. The rings are slid on to the shaft with the corners of the shaft aligned with the first ends of the arcs. Then the rings are rotated on the shafts toward the second ends of the arcs until the corners of the shafts jam against the inner edges. A special spanner wrench can be used to tighten and loosen the rings on the shaft.

A damped primary drive sprocket system is provided that may be directly driven by a motorcycle engine and may be arranged in a primary drive connecting the motorcycle engine to a motorcycle transmission. The damped primary drive sprocket system may include damper segments such as discrete isolator bushings arranged in leading and trailing slot chambers, on opposite sides of a lug within a slot of a coupling system that connects a hub to a sprocket within the damped primary drive sprocket system. The slot chambers may be circular in cross-sectional perimeter shape so and the isolator bushings may be cylindrical and fit snugly in the slot chambers in a manner that damps slight rotational clocking movements of the hub and sprocket with respect to each other during firing pulses of the motorcycle engine.

A non-prevalent order random sprocket for an internal combustion engine comprising a pattern of pitch radii, such that the radial variation of the pitch radii excite tensions at non-prevalent orders in a drive system of the internal combustion engine.

The present disclosure provides a captive sprocket system for an engine, comprising: a sprocket including a first sprocket gear, a second sprocket gear and a retaining disc having a diameter and a thickness; a cylinder block having a bore with a central opening and a plurality of threaded bosses, the plurality of threaded bosses together forming an axial support surface and a radial location surface, the axial support surface and the radial location surface being sized to receive the retaining disc of the sprocket to support and locate the sprocket; and a plurality of captivation screws configured to be received by the plurality of threaded bosses, each captivation screw having a head with a lower surface which, when the captivation screw is received by a threaded boss, overlies the retaining disc and retains the sprocket in the bore.

A bicycle rotor comprises a base portion and at least one chain engagement portion. The base portion is configured to rotate around a rotational center axis of the bicycle rotor. The base portion is at least partly made of a first resin material. The first resin material has a first Young's modulus. The at least one chain engagement portion is provided on the base portion. The at least one chain engagement portion is at least partly made of a second resin material. The second resin material has a second Young's modulus. The first Young's modulus is higher than the second Young's modulus.

To provide a sprocket that not only reduces impact and hitting noise caused by contact and seating of a chain when it meshes with the sprocket, but also simplifies a setting of process conditions for securing a cushion ring on a side face of a sprocket body. The sprocket includes the sprocket body formed with a plurality of teeth on a circumferential surface thereof, and the cushion ring provided to at least one side face of the sprocket body and having an outer circumferential surface that makes contact with link plates of a chain. The cushion ring is secured to the sprocket body without an adhesive layer.

To provide a simple-structured chain drive mechanism that can reduce the noise generated when the chain sits on the sprocket, prevent deterioration of power transmission efficiency, and reduce wear of the sprocket and chain. The chain drive mechanism includes a rotating shaft, a sprocket having a shaft hole, and a chain. The shaft hole is provided with a rotation transmitting groove on an inner circumferential surface thereof. The rotating shaft is provided with a rotation transmitting member that engages with the rotation transmitting groove. The rotation transmitting member is configured to be capable of relative sliding movement at least in a circumferential direction of the rotating shaft and capable of restoring relative positions of the rotating shaft and the sprocket.