Cushion shock absorber are not used to support the weight of the car, but to suppress the shock of the spring after the rebound and absorb the energy of the road impact. Shock absorbers and elastic components bear the task of slow impact and shock absorption, too much damping force, will make the suspension elastic deterioration, and even damage the shock absorber connector. Therefore, it is necessary to adjust the contradiction between elastic components and shock absorbers. In the compression stroke (the bridge and the frame are close to each other), the damping force of the shock absorber is small, so as to give full play to the elastic role of the elastic element and mitigate the impact. At this point, the elastic element plays a major role.