damper (Vibration Damper), when the shock absorber is mainly used to suppress the shock-absorbing springs and rebound after the impact from the road surface. When after a rough road, although the shock-absorbing spring can filter the vibration of the road, but the spring itself will have to reciprocate, and the shock absorber is used to inhibit this spring jump. The shock absorber is too soft, the body will be jumping up and down, shock absorbers too hard will bring too much resistance, hinder the normal spring work. In the conversion process on the suspension system, the shock absorber to be matched hard and stiff spring, and the spring stiffness of the vehicle weight and closely related, and therefore generally use heavier vehicles harder damper. It means in contact with the lead crankshaft shock, to counter the torsional vibration of the crankshaft (i.e., a crankshaft by cylinder firing impact force twisting phenomenon).