Tyre balance, also referred to as tire unbalance or imbalance, describes the distribution of mass within an automobile tire or the entire wheel (including the rim) to which it is attached.
When the wheel rotates, asymmetries of mass may cause it to hop or wobble, which can cause ride disturbances, usually vertical and lateral vibrations.
It can also result in a wobbling of the steering wheel or of the entire vehicle. The ride disturbance, due to unbalance, usually increases with speed.