Patent ID: 7395892

Claim:
A two-stage suspension assembly having a driven wheel rotatably mounted thereon, for use on a main cycle frame having a pedal assembly mounted thereon, the driven wheel and pedal assembly each having an axis of rotation and a distance between them, the suspension assembly being pivotally mounted on the main cycle frame, there being an endless flexible driving linkage between the pedal assembly and the driven wheel, the suspension assembly comprising: a first stage resiliently linked to the main cycle frame so as to allow a first degree of driven wheel travel, the driven wheel being displaceable upwardly relative to a surface the driven wheel is traveling over without substantially increasing the distance between the driven wheel and the pedal assembly, and a second stage resiliently linked to the main cycle frame and pivotally linked to the first stage so as to allow a second degree of driven wheel travel, the driven wheel being displaceable a further distance upwardly relative to the surface the driven wheel is riding over and the distance between an axis of rotation of the driven wheel and the pedal assembly being increased; both the first and second stages being active when no pedalling force is applied to the pedal assembly, and the second stage being substantially inactivated when pedalling force is applied to the pedal assembly due to a tension in the flexible linkage between the driven wheel and the pedal assembly, the first stage including: a swing arm having a wheel end and a frame end; a support arm having a suspension end and a frame end; and a first shock absorber having a first and second end and a spring rate; the driven wheel being rotatably mounted on the wheel end of the swing arm; the suspension end of the support arm being pivotally mounted on the swing arm at a first pivot point not adjacent the frame end of the swing arm and the first end of the first shock absorber being mounted on the swing arm at a position other than adjacent the wheel end thereof; and the frame end of the support arm being pivotally mounted on the main frame at a second pivot point adjacent the pedal assembly, and the second end of the first shock absorber being mounted on the main frame at a position not adjacent said pedal assembly, the second stage including a second shock absorber having a first end and a second end, the first end of the second shock absorber being mounted on the frame end of the swing arm and the second end of the second shock absorber and the frame end of the support arm being pivotally mounted on the main frame forming the second pivot point adjacent the pedal assembly, the first end of the first shock absorber being mounted at the first pivot point.