Rear suspension for bicycles

Claim 1

A bicycle frame comprising: a rigid generally triangular main frame including a top tube, a down tube, and a seat tube, and including a bottom bracket embracing a crank axis near the main frame lower apex, said crank axis defining an axis for rotation; a plurality of chainwheels of differing diameters mounted on said crank axis; paired right and left lower arm members each having a front and a rear end, said front ends of said lower arm members being pivotally connected to the main frame such that said lower arm members are pivotable about a lower arm pivot axis situated above the horizon of the bottom bracket crank axis; paired right and left upper arm members each having an upper and a lower end, said lower end of each upper arm member being pivotally connected to a respective one of said lower arm members such that said upper and lower arm members are pivotable about a rear pivot axis near said rear ends of said lower arm members, said upper arm members receiving a rear wheel axle at hub points located on a hub axis spaced above the horizon of said rear pivot axis; a plurality of sprockets of differing diameters mounted on said rear wheel axle; and means, associated with said upper ends of said upper arm members and pivotally connected to an upper pivot point situated at an upper portion of the main frame, for limiting the path of movement of, and for substantially continuously providing effectively all resilient resistance to movement of, said upper ends of said upper arm members.