Bicycle rear suspension

A bicycle rear suspension, which comprises:

• crank gear case means;
• frame means on which the crank gear case means is mounted, said frame means having an arm extending therefrom, said frame means including an upper tube, a saddle tube connected to said upper tube and a diagonal tube connected to said saddle tube;
• lower fork means pivotally mounted at a first end thereof to said frame means;
• upper fork means connected to a second end of said lower fork means, said upper fork means having axle bearing means mounted thereon which is driven in rotation by a chain of the bicycle wherein the upper fork means has an upper end which is pivotally connected to said arm of said frame means wherein said lower fork means, said upper fork means, said arm and said saddle tube form an articulated quadrilateral such that a straight line passing through an axis of rotation of a hub of the rear wheel, on the one hand, and a center of curvature of a path of said hub on the clearance of the suspension, on the other hand, forms with respect to a horizontal line extending parallel to a median longitudinal plane of the bicycle, an angle ranging between 10° and 20°, and wherein the suspension is prestressed so as to be set at a high stop position when the cycle is immobilized and a cyclist is in a seated position thereon.