Definition of Standing Wave

A standing wave is a deformation in the sidewall of the tyre in front of and behind the contact patch of the tyre. It is not usually possible to see this deformation under normal operating conditions but the photograph below, taken with a high speed camera, gives a good view of a standing wave generated in a tyre running at 280 km/h on a test rig:

Too great a standing wave results in excessive heat build up in the tyre and may lead to failure. The photograph below shows the areas of stress build up due to standing wave deformation: