Static imbalance can be determined by raising the car and letting the wheel spin arbitrarily: the center of gravity of the wheel will always be at the bottom. A wheel that has only a static imbalance bounces as it moves.
«Dynamic» imbalance only appears when the wheel is spinning fast. In this case, the heavier place is not located on the central plane of the wheel, but is slightly shifted outward or inward. At the same time, the wheel not only bounces, but also sways from side to side.
Wheel balancing
The wheels must be eliminated static and dynamic imbalance. There are two ways:
- The wheel is removed from the car and screwed to the balancing stand. There it spins and at the same time it is measured where and how much weight the lead weight should be installed on the wheel to compensate for the imbalance.
- To eliminate the remaining imbalance, it is necessary to carry out precise balancing. This also compensates for the imbalance of the wheel hub and the brake disc. Without removing the wheels from the car, they are spun by means of an electric motor with a friction disc to the required speed, while the residual imbalance is fixed. It is also leveled with lead weights.
Note. Recommendation: the front wheels do not need to be spun for precise balancing by the electric motor. One-way acceleration is detrimental to the differential mechanism. For precise balancing, the front of the Renault 19 is raised and the engine spins the front wheels in fourth gear to a speed of 90 km / h.