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.

A sprocket for a chain drive, in particular a timing chain drive for an internal combustion engine, is provided. The sprocket includes a radially outer toothed ring and a damping ring. The damping ring is axially spaced apart from, and radially inside of, the toothed ring. The damping ring has a radially outer surface that is shaped to be complementary to link plates of the timing chain. The design of the sprocket results in the damping ring being subject to practically no wear, being producible from a conventional material, and being economical to produce.

A driving force transmission system for an engine is provided with a crank sprocket mounted on a crankshaft, cam sprockets mounted on camshafts, an intermediate shaft disposed between the crankshaft and the camshafts, a dual sprocket mounted on the intermediate shaft, and including a first sprocket and a second sprocket facing each other in a state that the first and second sprockets are rotatable relative to each other, a first endless transmission member wound around the crank sprocket and the first sprocket, and a second endless transmission member wound around the cam sprocket and the second sprocket. The dual sprocket includes a damping portion for connecting the first and second sprockets. The damping portion is configured to exert a resilient force in a rotational direction of the first and second sprockets.

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 a first chain-engaging axial width which is smaller than a first distance defined between opposed outer link plates of a bicycle chain and which is larger than a second distance defined between opposed inner link plates of the bicycle chain. The at least one second tooth is adjacent to the first tooth and is disposed on a downstream side in a rotational driving direction of the bicycle sprocket. The at least one second tooth is configured to engage with inner link plates of the bicycle chain. 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.

A torsionally compliant sprocket system includes a first sprocket (250); a second sprocket (230) mounted in side-by-side relation to the first sprocket (250); a resilient member (270) that resiliently couples the second sprocket (230) to the first sprocket (250) to allow limited angular rotation of the second sprocket (230) with respect to the first sprocket (250); and a locking structure (300, 600, 700) that is biased toward an engaged position in which angular motion of the second sprocket (230) with respect to the first sprocket (250) is restrained and moves in response to rotation of the first sprocket (250) to a disengaged position in which angular motion of the second sprocket (230) with respect to the first sprocket (250) is permitted.

A sprocket assembly which is either driven by a drive chain or which drives the drive chain includes a hub centered about a sprocket axis and defining a hub radially outer surface; a plurality of sprocket teeth extending radially outward from the hub; and a cushion ring assembly adjacent to the plurality of sprocket teeth and circumferentially surrounding the hub radially outer surface. The cushion ring assembly includes a cushion ring adjacent to the plurality of sprocket teeth and circumferentially surrounding the hub radially outer surface; the cushion ring being resilient and compliant. The cushion ring assembly also each includes a retention ring which is partially embedded within the cushion ring and which engages the hub radially outer surface in an interference fit, the retention ring providing axial and radial retention of the cushion ring to the hub.

A silenced sprocket comprises, adjacent to the base of its teeth, a circular channel, or bilateral channel, on the metal body of the sprocket itself. The bilateral channel has a minimal radial extension, a silencing rubber element (106), and a bilateral channel. The bilateral channel creates its own housing and has a minimal radial extension compared to the sprocket radius. The silenced sprocket is made by a molding technique that uses special molding components, adapted to apply the rubber silencing element on the sprocket metal body. These components are of annular circular shape, U cross section and a width essentially corresponding to the channel width, rendering the mold independent from the specific shape of the sprocket metal body.

A compression ring of a chain sprocket is provided with improved wear characteristics and damping to match various forms of link plates of a chain assembly. The chain assembly includes a plurality of longitudinal link plates hingedly connected by a plurality of pins. The compression ring includes two arrays of compression pads, each array defined by a different profile. Each array of compression pads can be matched to two corresponding groups of link plates. Multiple forms of compression pads and link plate geometries can be accommodated. Compression pad damping force can be tuned by adjusting the width and/or height of the link plates.

A device that will allow a go kart to smoothly accelerate and decelerate particularly during racing the go cart. This device once assembled will allow the gradual absorption of shock on the drive chain as it rotates around thereby, rotating the axle of the go kart.

A rotatable assembly, such as a crankshaft or camshaft assembly, includes a first rotatable component and a second rotatable component coupled to the first rotatable component. The first rotatable component includes a first body and defines a plurality of recesses extending into the first body. The second rotatable component includes a second body and defines a plurality of protrusions extending from the second body. The protrusions are disposed inside the respective recesses to allow the second rotatable component to rotate in unison with the first rotatable component.