Wheels are balanced for safety reasons. A properly balanced wheel is such on which the weight is even around the axle. Such wheel spins over the road surface evenly without run-out. Rims and tyres are designed and manufactured in such a way as to facilitate this; however, to properly balance a wheel you must place the right weights in the right spots. Many drivers believe that balancing is required only when changing the tyres, whereas you should do it regularly, irrespective of tyre change.