Contact patch

The tire contact patch or the contact area is that part of the tire maintains contact with the road.

Only there can be built up forces ( "grip" ), so that the vehicle is guided tracking stability. In contrast to the car, which also has much larger and twice as many contact points, it is the bike a little palm-sized area at the front and rear tires. Modern tire technology makes it possible that this still speeds up to 300 km / h can be achieved.

The size of the footprint of a tire is dependent primarily on the wheel load (for example, by the weight of the vehicle ) and the tire pressure from, because the internal pressure of the tire bears the majority of the wheel load. As well as the tire width and the stiffness of the side wall play a role.

With the simplified assumption that there is no portion of the wheel load is transmitted to the road surface through the tire sidewalls, the total wheel load must be distributed and supported by the inner pressure of the contact surface:

Some (2012: few ) off-road vehicles have automatic systems that can cut down on slippery surfaces the tire pressure to cause a larger tire footprint. If the vehicle is stuck in soft sand or the like, it may help to deflate the tires of the drive axle (s). The Radpanzern mainly used by the military tire pressure control systems, however, are common.