Flat tire

A flat tire (British English: flat tyre) is a deflated pneumatic tire, which can cause the rim of the wheel to ride on the tire tread or the ground potentially resulting in loss of control of the vehicle or irreparable damage to the tire. The most common cause of a flat tire is puncturing of the tire by a sharp object, such as a nail or pin, letting the air escape. Depending on the size of the puncture, the tire may deflate slowly or rapidly.^[1]

Besides puncturing of the tire a flat can be caused by: failure of or damage to the valve stem; a nail in the tire; rubbing of the tire against the road; ripping of the tire; separation of tire and rim by collision with another object; excessive wear of the tire tread allowing explosive tire failure or road debris tearing through the tire. Some tyres, particularly those with a slow leak, can be repaired and re-inflated; others, especially those with worn tread, must be replaced.