When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
from my experience with hammered front fenders and shaven rears, the rubbing comes from the fronts' frame only over bad bumps, not from any of the fenders. but then again I run pretty conservative wheel specs and a slight stretch all around. reference
I rub on my front fenders from time to time when doing a hard turn on high speed. Other than that it's just the wheel well in the front when going over bad bumps, like ArodDaLob said. My rear is pulled aggressively to even rub.