Mountain bicycle with rear suspension having neutral braking trajectory

A bicycle, 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 pivotably attached to the main frame, the rear wheel suspension system comprising:
• an upper link pivotably attached to the main frame at a first pivot point;
• a rear stay member having an upper end pivotably 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;
• a lower link pivotably 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 pivotably 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 pivotably connected to the upper link and a second end pivotably connected to the main frame, the shock absorber operating between an uncompressed configuration and a fully compressed configuration;
• 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, the instantaneous center of rotation displacing along a trajectory as the shock absorber operates between the fully extended configuration and the fully compressed configuration;
• and
• wherein, as the shock absorber and thus the rear wheel suspension compresses from the fully extended configuration to the fully compressed configuration, the instantaneous center of rotation displaces from a first position located rearward of the bottom bracket to a second position located in front of the bottom bracket, and wherein the instantaneous center of rotation travels through an inflection point between the first and second positions, the inflection point corresponding to a position where the upper axis and the lower axis are parallel to each other and the instantaneous center of rotation is defined at infinity.