US Patent 8152191 Bicycle suspension system

A suspension system may include a front frame connected to a front wheel, a shock absorber pivotally connected to the front frame, and a rear frame connected to a rear wheel supported by a ground contact point. The shock absorber may include a preset pressure substantially equal to a pressure caused by a body weight of a rider. The suspension system may be structurally configured to maintain an instantaneous center point of movement of the rear frame relative to the front frame within an angle range of about 45°±15° relative to the ground contact point when the rear frame moves relative to the front frame.