Trail (steering geometry)

In chassis geometry, trail is the distance measured along the ground between the point where the steering axis meets the road and the centre of the front tyre's contact patch, which lies behind it. Trail is created mainly by the rake angle and the fork offset in the triple clamps.

Trail makes the front wheel want to run straight, like the castor wheel of a shopping trolley. More trail gives stability at speed and calmer steering; less trail makes the bike turn more quickly but can make it nervous.

Changing fork height in the clamps, rear ride height, triple clamps with a different offset or a different tyre size all change trail. Make such changes in small steps. The word trail also refers to an off-road route.