Slip angle

In vehicle dynamics, slip angle or sideslip angle is the angle between the direction in which a wheel is pointing and the direction in which it is actually traveling (i.e., the angle between the forward velocity vector ${\displaystyle v_{x}}$ and the vector sum of wheel forward velocity ${\displaystyle v_{x}}$ and lateral velocity ${\displaystyle v_{y}}$, as defined in the image to the right). This slip angle results in a force, the cornering force, which is in the plane of the contact patch and perpendicular to the intersection of the contact patch and the midplane of the wheel. This cornering force increases approximately linearly for the first few degrees of slip angle, then increases non-linearly to a maximum before beginning to decrease.

The slip angle, ${\displaystyle \alpha }$ is defined as