An object of the present invention is to provide a sprocket that mitigates the impact of tension fluctuations resulting from load torque changes, suppresses noise and vibration, ensures stable chain behavior, prevents sprocket durability loss and the generation of harmonics during rotation, along with a chain drive system. Tooth roots between adjacent teeth of the sprocket include those with a radial deviation from a root circle of a standard tooth profile, set within a predetermined numerical range corresponding to a tooth pitch. A phase variation pattern is created by changing a root radius in accordance with an angular position. The phase variation pattern has a waveform with an amplitude varied within a range of ( 1/7)Amax, where Amax represents a maximum amplitude. The chain drive system includes a plurality of sprockets and a chain passed over the sprockets, at least one of them being the above-described sprocket.

To provide a sprocket that reduces the influence of tension fluctuations concurrent with load torque variations, that suppresses noise and vibration, and that prevents an increase in tension fluctuations, noise, and vibration even when the chain tension is low and the load torque is small, or in regions where a chain and the sprocket engage without being affected by the tension. The sprocket has a plurality of teeth mating with the chain that are provided with an equal pitch therebetween, and that include teeth with different working pressure angles relative to the chain.

A chainring for a bicycle includes a body and a plurality. The plurality of teeth are disposed about a periphery of the body. The plurality of teeth have a tooth body formed of a first material and include a load flank. The plurality of teeth also include an insert formed of a second material. The insert is coupled to a tooth body of the plurality of teeth forming a load flank surface of the plurality of teeth.

A front sprocket assembly basically includes a front sprocket, a sprocket carrier and at least one slide shaft. The front sprocket includes a sprocket body having at least one carrier mounting portion. The at least one carrier mounting portion has the at least one slide opening. The sprocket carrier includes at least one sprocket mounting portion. The at least one sprocket mounting portion has a first shaft-supporting portion and a second shaft-supporting portion. The at least one slide opening receives the at least one slide shaft between the first shaft-supporting portion and the second shaft-supporting portion.

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 first radial-tooth height is greater than the first chain-engaging axial width. The at least one second tooth has a second radial-tooth height. The at least one second tooth has a second chain-engaging axial width which is smaller than the second distance. The second radial-tooth height is greater than the second chain-engaging axial width. The first radial-tooth height is greater than the second radial-tooth height.

A roller chain sprocket includes a body with a hub and a row of teeth that extends circumferentially around the hub such that the hub extends axially outward on opposite first and second sides of the row of teeth. The teeth are separated from each other by tooth spaces, wherein each of said tooth spaces is bisected by a radial tooth space centerline. First and second elastomeric cushion rings are respectively bonded to the hub on the opposite first and second sides of the row of teeth, with cushion ring extending circumferentially about the hub and including a plurality of compression pads separated from each other by axially extending transverse grooves. Each of the compression pads includes a planar or otherwise flat outer surface that is connected to a respective preceding one of the grooves by a leading corner surface and connected to a respective trailing one of the grooves by a trailing corner surface. Each of the grooves is located radially inward from a respective associated one of the tooth spaces such that the tooth space centerline is circumferentially aligned with the trailing corner surface that connects the groove to a preceding one of the compression pads. The compression pads provide both primary compression for a meshing chain link row and secondary compression for the next-meshing, upstream chain link row.

A number of variations may include a sprocket using one or more slot(s) and/or compressive or elastic material in order to lower the NVH. A number of variations may include a sprocket which isolates the vibrations created by the impact of the chain with the sprocket so that the vibrations are prevented from traveling into the shaft.

The present invention provides a rotation transmission mechanism including an internal rotation member and an external rotation member rotatably arranged with respect to the internal rotation member. The internal rotation member has one or a plurality of outer-peripheral-projected portions protruding toward an outer-peripheral side. The external rotation member has one or a plurality of inner-peripheral-projected portions. The outer-peripheral-projected portions have a forward-movement surface located at a position displaced from a center of the outer-peripheral-projected portion in a forward movement direction in which the rotation transmission mechanism rotates by forward movement. An elastically-deformable portion is disposed between the forward-movement surface and the inner-peripheral-projected portion. A space is partially formed in the elastically-deformable portion. When the internal rotation member rotates relative to the external rotation member, the elastically-deformable portion is sandwiched between the outer-peripheral-projected portion and the inner-peripheral-projected portion and is thereby elastically deformed.

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.

The invention relates to a damping device on a multi-gear cassette for a rear wheel of a bicycle, wherein percussive forces produced by the chain members running from the slack span of the chain onto the sprocket are damped. This is achieved by damping the chain in the region of the chain run-in on the sprocket where no loads are borne. In one embodiment, a damping ring is provided for the purpose of supporting the chain link plates, and the tooth contour of the tooth flank which does not transmit load force is set back, and the tooth root space according to the invention is recessed toward the hub center. As such, when the chain is fed in to the sprocket, the chain link plate contacts the damping ring rather than the chain roller impacting the tooth flank or the tooth base.