Oh, and for grip driving your spring rates are dictated solely by how much tire grip you have.

If you do not have enough spring rate you will compress your suspension too much under braking or acceleration and have no travel left for bumps.

With 7/5 and 245 DOT Rs it is apparently possible to use all your suspension travel under braking, crossing a road crown and hitting bumps (top of my fender liner has tire wear).

If you had 12 inch slicks up front you would obviously need a LOT more spring rate to keep the front bumper off the pavement.

 

Not entirely, if your ride height is higher, you can go softer. If you have adjustable length shocks, you can set it up to take the full weight on the bumpstops before the tire hits the fender.

 

Assuming you have more shock stroke available. In a situation like mine where tire hits the top of fender, you are absolutely correct. But that is bad set up on my part.

Yep, but bumpstops are a way to raise your spring rate progressively :P Is your damping set up to include the bumpstop rates though?

It may have more traction over bumps if you are not on the bumpstops.