Motorcycle shock absorbers can dampen the vibrations transmitted to the vehicle body caused by uneven roads or poor driving conditions, quickly eliminating the vibrations of the axle and wheels caused by the ground, ensuring that the wheels always grip the ground, thereby guaranteeing the vehicle's steering and braking functions.

Motorcycle shock absorbers must, on the one hand, support the vehicle's safe driving functions, such as grip, braking and acceleration, etc. On the other hand, in order to achieve the best possible level of comfort, it must also reduce the transmission of vibrations to as low a level as possible.

In the suspension system, due to the impact on the elastic elements, vibrations occur. To improve the ride smoothness of the vehicle, motorcycle shock absorbers are installed in parallel with the elastic elements in the suspension to attenuate the vibrations. Most motorcycle shock absorbers are hydraulic shock absorbers. Their working principle is that when the frame and axle are subjected to vibration and undergo relative motion, the piston inside the shock absorber moves up and down, and the oil in the shock absorber cavity repeatedly flows from one cavity through different pores into another.

At this point, the friction between the hole wall and the oil, as well as the internal friction among the oil molecules, form a damping force on the vibration, converting the vehicle's vibration energy into the heat energy of the oil, which is then absorbed and dissipated into the atmosphere by the shock absorber. When the cross-section of the oil channel remains unchanged, the damping force increases or decreases with the increase or decrease of the relative movement speed between the frame and the axle (or wheel), and is related to the viscosity of the oil.

Elastic elements and shock absorbers are responsible for mitigating shock and vibration. Excessive damping force will deteriorate the elasticity of the suspension and may even damage the shock absorber connectors. During the compression stroke, the damping force of the shock absorber is relatively small to fully exert the elastic effect of the elastic element and mitigate the impact. At this point, the elastic element plays a major role.

During the suspension extension stroke, the damping force of the shock absorber should be large to quickly reduce the shock. When the relative speed between axles is too large, the shock absorber is required to automatically increase the fluid flow rate to keep the damping force within a certain limit at all times, so as to avoid bearing excessive impact loads.