roll centre height

[faeez]

how high can the roll centre be from the ground before jacking actually occurs? How do I know how high i can place it?

[faeez]

how high can the roll centre be from the ground before jacking actually occurs? How do I know how high i can place it?

[BilletB]

With the way you're thinking of it if your "roll center" is anywhere but exactly on the ground you have jacking. Period.

[C.Zinke]

You can not determine if you have jacking by looking at the roll-center height. It is much more complex. The one way to figure out if you have jacking is to calculate all loads in every link of the suspension. Or you could use multibody simulation software.

for example: Lets say you have an inclined toe link, such that the inner chassis pickup point is much lower than the pickup point at the upright. If you have a torque about the steering axis of the upright due to trail while cornering, than it happens that the force of the toe link pulls the wheel up or down, depending on the direction of the torque.

This is only one example that shows that you can not just look at the rollcenter. Rollcenters are good to get rought estimations. But not more.