Originally Posted by wolfwyndd
Before I get new tires I had to first replace the loose stablizer bar in the rear that was causing the cupping in the first place.
That's the first time I've ever heard of a sway bar causing a tire to cup. A sway bar really doesn't dampen a spring in any way. Sway bars simply transfer weight from one side of the car to the other. Cupping is caused by a spring not being properly dampened (allowing the tire to bounce up and down uncontrolled due to a worn out shock). To a lessor extent, and out of balance tire can result in a cupping pattern as well.