What deos caster do?

[DirtyBirdRacing]

Hi,

I have searched this website and others and have found that the only thing that caster deos for you is to make your wheels straight themselves out after you go around a turn and loosen up your grip on the steering wheel. Is this all it deos, what else deos caster do.

Thanks,
Bill

 

[DaveDSM]

The caster angle refers to the longitudinal inclination of the steering axis. It creates a self-centering force that is somewhat different from the one created by the lateral steering axis inclination. A positive caster is established when the steering axis meets the ground ahead of the center point of the contact patch (a point directly under the axle). Most passenger cars have a positive caster on the order of 0 to 5 degrees. A positive caster causes the wheel to trail behind the steering axis. When the vehicle is steered, the caster angle develops an opposing force that tends to steer the vehicle out of the turn.

Another effect of caster angle is that it causes the camber angle to change when the wheels are steered. When the vehicle is steered, the inside wheel progresses into a positive camber and the outside wheel progresses into a negative camber. Considered independently of steering axis inclination, the effect of caster in a turn is to drop the side of the vehicle on the outside of the turn and to raise it on the inside of the turn.

 

[DirtyBirdRacing]

Thanks, once I got done the whole longitudinal and lateral thing it all made it much clearer.

Thanks a lot,
Bill