As the engine, steering system, braking performance and aerodynamic body aspects of continuous improvement, to make the vehicle speed continues to increase. At high speeds, the imbalance of the wheel assembly (tire plus wheel disc) will produce vibration and suspension components by the vibration transmitted to the vehicle body, so that the driver and passenger discomfort (see Figure -4). Therefore, to correctly balance the wheel assembly, in order to eliminate this vibration.

1, static balance

The mass distribution of the wheel assembly is mounted on the journal, if the quality of the tire around the wheel axis uniformly distributed, at a particular point on the wheel can be at rest in any position. In this case, you can think of static wheel assembly has been balanced (see Figure -5). Static balance refers to the radial mass balance in a stationary state.

2. Balancing

Balance refers to the mass balance in the axial rotation of the wheel (see Figure -6). Wherein, A and B are two weights on the tire. G0 is assumed that the center shaft; center of gravity Gl of the weight of A; B the G2 is the center of gravity of the weight; the weight of the F1 A force, F2 is the force of the weight of the block B; the weight of the FA A tangential force; FB as weight B tangential force. According to analysis, the wheel assembly in a stationary state, there is no dynamic imbalance.