I was cleaning my Fatboy yesterday and discovered something really cool. I accidentally spray Castrol super clean onto the solid wheel, guess what? The yellow stain on the wheel came right off, wheels look brand new. You don't want to overdo thought, I mixed 1/3 super clean to 2/3 water, it turned out perfect. Please don't leave the cleaner on for more than 1 minute, rinse it off throughly. Just want to share.
I use simple green the same way. when i polished the wheels with a powerball, i got black on the middles of the rim. I try several times to clean it off, without any luck. I sprayed simple green on them and they look awesome.