I picked up a 2006 Softail Deuce w/ 3500 miles on it for a great price last summer. The previous owner replaced the 21" Front tire with an 18" fat tire. The only problem is the front fender isn't on the bike. I put it back on but it rubs the tire. I would like a fender on the bike so it does what fenders do, keep road debris, water, etc off the rider (me). It looks like I have a several of options. Putting a 21" narrow wheel back on, finding a fender that fits, replacing the front fork with a wider fork so I can get a wider fender. There are probably a number of other options.

I was wondering, would it be easier to get a narrower 18" tire and have it installed along with the original fender and is my fender clearance the function of a tire that is too wide?

I kind of like the way the bike rides and handles with the 18 wheel. WIth the tire mounted it sits about an 1 1/2" lower than with the 21" stock wheel and tire. So if going to a slightly narrower tire works I'd like to go that route.