Well, I have the Planet Bike Clip-on Freddys, for 26 to 35 tires, and they have worked great so far on my eyeletless, Gitane cross frame. The frame is really tight by current, quasi-mtb CX standards, but I can fit Ritchey Speedmax 30s in there for snowy/muddy days. Like today.

I had an incredible amount of anxiety about buying them, since everyone seemed to slam clip-ons generally as worthless, but I didn't see anyone slam the Freddy clip-ons, so I gave them a chance.

The front fender is pretty darned bomber--the fork crown isn't even drilled, but it was easy to use two zipties to straddle the crown. I have a pop bottle mudflap on the front. At the end of my 10 mile commute with 1.5 miles on snowy, muddy canal path, my gaiters were utterly spotless. The rear fender is a bit less stable. It's rock solid at the BB (zip tied) and so-so at the seat stay bridge (again, undrilled, so it's ziptied to a wierdo, lame-fitting hanger thingy that Planet Bike includes). At the back fender stays, the fender is very secure, but flexy laterally. Under harsh conditions, I get a little rattle, but I heard no rubbing at all-- even today, when all of the downed branches on the canal path from yesterday's snow fall meant lots of 2 and 3 inch barriers to hammer over. On smooth road, I don't even know I have the fenders. So for performance, I have no beefs.