A bicycle frame set comprising a main frame and a rear wheel suspension system including a swing-arm, a first link member and an intermediate lower link member. The swing arm has a forward end pivotally connected to the main frame. The swing-arm pivots such that a rear wheel axle on the swing-arm pivots about the lower pivot point on the frame with a constant radius of rotation. The first link member is pivotally connected to the main frame at a link pivot point, and has a displaceable lower end pivotable about the link pivot point. The intermediate lower link member is pivotally connected between the first link member and the swing-arm. The first link member rotates in a direction opposite to the rotation of the swing-arm as the suspension system compresses. A shock absorber is disposed between the first link member and the main frame.