Bicycle rear wheel suspension

Claim 1

A rear wheel suspension system for a bicycle, where the bicycle includes a bicycle frame comprising a main frame portion and a rear frame portion having a rear frame pivot in the region of a bottom bracket shell, wherein the rear wheel suspension system comprises: a shock absorbing system between a seat member of the main frame portion and the rear frame portion including (a) an inner member mounted on one of the main frame portion and the rear frame portion and an outer member about said inner member whereby said inner member is generally axially slidable in said outer member which is mounted on the other of the rear frame portion and the main frame portion, whereby the rear frame portion moves arcuately about said rear frame pivot and the inner and outer members move substantially axially over one another, when a shock loading is received on the rear frame portion and the seat member, the inner and outer members have two bearing surfaces on their external and internal opposed sides respectively, these bearing surfaces allowing substantially axial movement of the inner member within the outer member but precluding twisting of the inner and outer member and the rear frame portion to which one of the inner and outer members is attached, thereby providing a torsion lock on the inner and outer members and therefore a torsion lock on both the pivoting rear frame portion and suspension system; (b) a shock absorber mounted between said seat member and said rear frame portion; (c) a stepload system wherein a stepload pin is located and fixed through the outer member, a stepload slot in said inner member in which said step pin moves whereby the limit of the inner member's slot prevents the stepload pin and subsequently the outer member and the rear frame portion from fully returning to a position where the shock absorber is unloaded, which results in a steploading of the shock absorber and suspension system such that only a shock loading on the rear frame portion greater than the steploading permits suspension system articulation; and (d) an axial adjusting screw of the length of said stepload slot incorporated in the inner member, whereby movement of the adjusting screw decreases and increases the length of the stepload slot thereby respectively increasing and decreasing the steploading on the shock absorber and suspension system.