Pneumatic trail
![Bike tire contact patch during a right-hand turn.](/Images/godic/202502/03/Tire_pneumatic_trail5614.png")
Pneumatic trail or trail of the tire is a trail-like effect generated by compliant tires rolling on a hard surface and subject to side loads, as in a turn. More technically, it is the distance that the resultant force of side-slip occurs behind the geometric center of the contact patch.