In a wheel (tyre, inner tube, fitting rim, brake drum, etc.) the weights are generally never evenly distributed, both along the circumference and transversally. This causes various tyres of vibrations which are transferred to the vehicle from the wheel both through the drive elements and through the suspension. The amplitude of the vibrations is proportional to the size of the weights and depends on the speed rating. In order to eliminate these vibrations, balancing is performed by adding one or more weights (counterweights) applied to the rimbalconies. Three types of imbalance can be identified: static, dynamic and torque. Fixed or mobile installation balancing machines are generally used for balancing a wheel.
By adding small amounts of lead weights to the wheel, it is possible to equal out any unevenly distributed weight which may be present in the tire or wheel. Proper balance helps eliminate unwanted wheel and tire vibrations, and uneven wear caused by an out-of-balanced tire and wheel condition.