The topic of size change comes up from time to time. The issue with a 17 or 18 inch tire would be the curve of the rear fender and the curve of the tire. The fender is arched to look right with a 20 inch tire. I guarantee problems trying to fit an 18", and a 17" would be funny looking, I bet. Maybe adapt an 18" rear tire and put on a set of Bulldog Bagger or custom stretched Harley saddlebags to hide the rear wheel. Beats sitting home. Last time Blacktopper and I were at Strokers in Dallas, the shop manager Derek was doing a project fitting an 18 inch rear tire on a Wolf. Derek has left Strokers for another job and I never knew how it turned out. The guy (Chase Holbrook) in Utah who as selling the Wolf tires for a grand a copy is the guy who owns a used car agency, the Auto Realm. He has sold quite a few BIg Dogs, and I almost bought a Wolf from him a year or so ago. He never mentioned any tire issues, and of course when I became aware of it, lost interest. I understand supply and demand, but $999 for a tire made in 2008 or 2009----Really?? Anyhow, hats off to ChuxBD (Chuck) for his initiative in engaging Avon. I would mos' def' encourage you to try Shinko too. I can't speak for Matt or Derek/Donna, but I'm sure they would want to stock some of the tires too. Of course the issue is how many. Everyone who owns a Wolf should be interested in one or two tires at some point. Again, the issue is finding them.