i have a frame that does not allow that much fender clearance.
i had to take the fenders off.
there is a section of bike path with small pine needles that must be coated with super glue because if i ride over them, they dam up the wheel so bad that one time the rear wheel actually locked up. now this was on wet pavement with needles, so coef. of traction was down a bit.
cleaning those needles out of the tire/fender area was a pain. i even tried coating the insides of the fenders with teflon tape but those sticky needles did not care one bit.
oh, and these fenders were only about 6 inches long each. i just wanted to protect the brakes and not get stuff up the steering tube.
my average speed went up about 2 mph after i removed the fenders.