Trackday slicks part #4 - how did it go?

During the winter I modified the rear calipers to fit 13" rims, and this weekend was the first test how it worked out.

Well..

First impression was that it didn't. Lots of scrape marks on the inside of the rims and I was really concerned that the rims were ruined.

After a closer inspection, I believe the scrape marks are not from the calipers themselves, but from gravel trapped between the calipers and rims. They are very shallow and I don't think it's anything to be bothered about except maybe for visual appearance. Brake dust, old tire rubber for sure doesn't improve the look of things...

I might give the calipers another go with the grinder just in case.

UPDATE:


After another track day I did have another go with the grinder. After trying several different ways to measure clearance I found the best way was to tape a small drill on the inside of the rim and see where it touches the caliper. Now I'm certain I have at least 2 mm clearance everywhere.

I also took a black pen and painted the edges of the caliper, so if it touches the rim again I can see exactly where I need to grind some more.