If a vehicle has positive caster on one side and zero caster on the other, which direction will it pull?

When a vehicle has positive caster on one side and zero caster on the other side, it creates an uneven steering geometry. Caster refers to the angle formed by the steering axis when viewed from the side of the vehicle; positively angled caster generally aids in straight-line stability and steering returnability.

In this scenario, the side with positive caster will have a tendency to pull more towards that side during movement. The wheel with positive caster will want to return to its straight-ahead position more effectively compared to the wheel with zero caster, leading to the vehicle pulling in the direction of the wheel with a higher caster angle.

Consequently, if the positive caster is on the left side, the vehicle will tend to pull to the left. This deviation occurs due to unequal force distribution and balancing effects between the two sides of the vehicle. It is essential to ensure that both sides have similar caster angles for proper alignment and handling characteristics.