MBeliever

All cornering wheels slide because they are changing their rolling direction, but, the phenomenon of slip angle only occurs when the tread does not slide. This sliding fact is proven by simply studying the travel of a wheel through a turn and noting the vertical axis rotation of the wheel as it proceeds. No matter how flexible the rubber on a tire, the tire has to slide to change direction and follow the curved path. Slip Angle is tied to the belief that the tire tread is laid on to the road and stays in place on the road until it reaches the rear of the contact patch. Slip angle phenomena such as relaxation length, pneumatic trail and self-aligning torque are all dependent on the entire contact patch not sliding at any time while the tire proceeds through the turn. This is an impossibility proven by geometry and experiment and is demonstrated in the linked video below.