I hear bikes with long(er) reach calipers generally have clearance for fenders. What I don't understand is where you attach these... Don't caliper breaks use the holes in the fork crown and break bridge? and don't fenders use those same holes?
If anyone could clear this up, it'd be much appreciated.
Generally, both fenders will have an 'L' bracket on the crown; you remove the caliper put the fender in place, with the bracket between the caliper and fork (or brake stay). On full fenders there will also be braces that connect to the eyelets on the forks and rear dropouts.
The brake bolt supports the fender bracket. I mount mine so the bracket is just beneath the nut, with a washer on top.
Modern caliper brakes use a allen nut which is recessed into the frame, which does not adapt well to support a fender. The older ones with a simple nut are much better.