I ride a YZ 250 (2001). I've always encountered a small problem with the silver Excel rims, I've had on various motorcross bikes. Although I keep my machines in a clean, well maintained state always; I seem to get a clouding type of effect on the rim surface. It seems to lose that metallic chrome like finish, and starts looking dull and clouded for some reason. Yet other makes of machines I've had such as Honda that don't have Excel rims, I have no problem with. I use a common detergent when cleaning the bike (CT18); according to the advice I can get, it isn't too harsh and I should have no trouble with this product. So I'm at a bit of a loss as to what the solution may be.