Right now, there is about 5mm or so of clearance between the top of the tire and the front portion of the fender. It's really hard to see between the tire and the underside of the front portion of the fender, but the fender doesn't seem to impede tire motion.

There is a faint squeaky sound every time the tire goes round. It's so faint I wouldn't hear it while riding outside...only when I'm at home alone, and it's quiet, and I put my ear up to the fender. I can't seem to make the sound go away. The tire spins freely--doesn't grind to a halt. I'm wondering if it's the little tire knobby thingies hitting the fender...or if it's rubbing somewhere since the tire is slightly out of round. I have the fender jammed all the way up into the fork, hence the interest in shaving some material from the inside of the crown. If I could shave just a little material off the front of the fork crown to make it follow the curvature of the fender rather than being square, I could raise the front of the fender a bit higher. Thoughts?

It's crazy but in the rear wheel I have huge amounts of space. I really want to stick with this size of tire. Should I just run with it? I've already played with widening the fender profile--problem is that it reduces the overall diameter of the fender.