Trail braking

Depending on a number of factors, the driver fully releases brake pressure at any point between turn-in and the apex of the turn.

This technique is commonly used when racing, but can enhance control, increase sight distance through the turn, and add evasive options for street riders.

[9][10] Spencer and Ienatsch say the physics of angular acceleration mean that the slower any vehicle is going, the tighter the radius of the corner it can navigate.

[11] Spencer said that for every radius, motorcycle, and rider combination there is a maximum speed at which the turn can be navigated without exiting the road or suffering a low side crash.

In order to be properly performed, the driver must have excellent sense of the vehicle's behavior and be able to keep the braking effort within very tight limits.

In this technique, brake pressure is applied slightly later than usual upon deceleration, and is maintained during steering input, sometimes all the way to the apex.

As compared to the traditional circular entry, trail braking reduces the time for the requisite direction change needed to reach the driver's chosen apex.

[13] With the traditional corner entry where all deceleration is completed prior to steering input, the vehicle carries a constant speed and radius to the apex.

The combined peak tire forces act on the car perpendicular to its direction of travel to accelerate it toward its current turn center.

The combined vector force acting on the vehicle's center of gravity accelerates it in a more rearward direction as shown in the illustration.