I was going to reply to this the other day and then the forum went wonky.
What's the backspacing on the stock Tracker 15" wheels?
I wouldn't run anything wider than a 7" wide tire on a 235. You wouldn't have much sidewall bulge between the rim and tread on a 9.5" wide tire mounted on a 7" wide rim.
There are several companies that make special backspacing wheels. I also know that if you go to
www.summitracing.com 's catalog you can look at the wheels and then search through them based upon their width, bolt pattern, and backspacing. There's a lot of options in the Suzuki 5x5.5" bolt pattern.
Getting sick of those 245 MTR's already?