Heard others with Z520R's having the same issue on the Z520/Z521R FB page (and here on BBC), so I checked mine and sure enough I had some minor signs of rubbing on my inner fenders. Got the torsion axles adjusted two splines and the paint on the wooden inner fenders was peeling so being OCD I sanded them down and sprayed on several coats of a Line X type spray on them. Went ahead and cleaned the rims and wheels while I was at it. I should be good now...