Originally Posted by
unterhausen
I don't think I'm the only builder that has aimed for 10mm and gotten less. It's okay, but I hate the sound of gravel scraping the inside of the fender.
If you don't like gravel, you should try mud. A while back I hit a muddy road with fenders, probably an average of 15-20 mm clearance. It sounded like the bike was hawking and spitting all the way down that stretch: mud accumulating on the tires and scraping the fender (haw-w-w-w-k) and the flying off (spit). I was happy to get off that stretch!