I also had to shave my 4.25" on my cr500 with a 150 DOT. Actually didn't shave it; the chain did all the work. I couldn't use that 1/4" of the tire any way; too pinched. That was when I read about offseting rim with spoke adjustments, but got rid of the bike before I did anything.

I talked to Chuck one time in the pits about his bike. He had a 5'' rear with a 165 slick and zero chain rub. He had rim offset and sprockets spaced with chain guide removed. He also had Madman engineering tranny gear which spaces out 3rd, 4th, and 5th. With 15/39 gearing I could only pull 105mph. He had the same 15/39 but could pull 120mph with the Madman kit. I looked it up and its $800 for the parts.

There's a guy named Rick Pearce who races a cr500 in AMA Supermoto Unlimited class. He runs a 5.5" rim with a 170 or 180 series slick. He had his swingarm notched and rewelded with aluminum plate. I seen a pic of it somewhere. If I can find the link I'll post it. That's going to great lengths and probably pretty pricey unless you know a competent welder that can weld aluminum, but well worth it.



p.s. just took delivery on that 650 berg mentioned earlier. It will walk my old 500 easy. Been wanting to do some mra stuff for the last 2 seasons. hopefully this will be the year. for cost reasons I'll probably have to get smoked by the 600's in superstreet first then get my license and meet you guys in colorado class.