Im having a lot of difficulty installing rear 35mm planet bike cascadia fender on Salsa Casseroll. Bike has 700x28 Gatorskins on it. The black clip that attatches the fender to the rear brake bridge is rubbing substantially against the tire. I have the fender postioned as high as possible against the bottom of the caliper too. What am I doing wrong?? They advertise these as working with tires up to 28mm, which mine are. I would really appreciate any advice. BTW, the front installed relatively easily, but rear is a bear!!!