What does the term "caster angle" refer to in suspension geometry?

The term "caster angle" refers specifically to the angle of the steering pivot point. It is measured in degrees and indicates the forward or backward tilt of the steering axis or pivot point, which is located at the upper and lower control arms where the steering knuckle connects. This angle plays a crucial role in the stability of the vehicle while it is in motion and affects the steering response.

A positive caster angle usually means that the top of the steering axis is tilted back toward the driver, which enhances directional stability and helps maintain the vehicle’s straight-line tracking. This effect is especially beneficial during high-speed driving. Conversely, a negative caster angle can lead to a less stable steering feel and a tendency to wander.

Understanding the caster angle is essential for mechanics and technicians as it influences handling, steering feel, and tire wear. Other options provided do not accurately describe the concept of caster angle; they pertain to characteristics of wheel alignment or suspension settings but do not define the specific relationship of the steering pivot point to the ground or vehicle body.