Patent ID: 6843494

Claim:
A rear wheel suspension system for a chain-driven two-wheeled vehicle having a frame having a bottom bracket, and a rear wheel which rotates about a rear wheel axle at a distance from the bottom bracket, the suspension system comprising: a multiple member linkage assembly which is pivotally attached to the frame at two separated locations, the linkage assembly including a rear stay member and a lower linkage member, the rear stay member, at its lower end, supporting the rear wheel of the vehicle at its axle in a manner such that the rear wheel is able to move generally vertically with its axle moving from a lowermost position upward along a generally vertical wheelpath, such that the distance between the bottom bracket and the rear wheel's axle increases continuously as the rear wheel's axle is caused to move upwardly from its lowermost position along the wheelpath, and such that the rate of the change of distance between the bottom bracket and the rear wheel's axle either remains essentially constant or changes continuously in only a single sense over the movement of the rear wheel's axle upwardly from its lowermost position along the wheelpath, and the lower linkage member being pivotally connected to the frame at one of said locations and pivotally connected rearwardly thereof to an intermediately located point on the rear stay member which is above the axle of the rear wheel when the rear wheel is in its lowermost position relative to the frame; and a shock absorbing and damping device affixed between a member of the linkage assembly and either the frame or another member of the linkage assembly to cause the rear wheel to maintain as continuous a contact as possible with a surface over which the vehicle is ridden despite the presence of irregularities in the surface.