Patent ID: 7635141

Claim:
A bicycle frame set comprising: a main frame including at least a seat tube, a top tube, a head tube, a down tube, and a bottom bracket fixed to at least one of the seat tube and the down tube; and a rear wheel suspension system pivotally attached to the main frame, the rear wheel suspension system comprising: an upper link pivotally attached to the main frame at a first pivot point; a rear stay member having an upper end pivotally attached to the upper link at a second pivot point and a lower end having a dropout receiving a rear wheel axle of the bicycle, the rear wheel axle defining an axle axis about which the rear wheel rotates when mounted to the dropout; a lower link pivotally attached to the main frame at a third pivot point located on said main frame at a lower vertical elevation than the first-pivot point, and the lower link being pivotally attached to the rear stay member at a fourth pivot point located on said rear stay member below said upper end thereof; and a shock absorber having a first end pivotally connected to the upper link and a second end pivotally connected to the main frame; wherein an instantaneous center of rotation is defined at an intersection between an upper axis extending through the first and second pivots and a lower axis extending through the third and fourth pivots, and an average chain torque line of the bicycle frame set is defined as an average of a number of possible chain torque lines extending along a tension side of a chain when the chain is positioned on chain sprockets of the bicycle frame set; and wherein, throughout a travel distance of the shock absorber, the instantaneous center of rotation remains below the average chain torque line, the lower axis remains above the axle axis, and a portion of the lower axis defined between the third and fourth pivots extends below the average chain torque line.