Hey folks, major noob question here... Since it's winter and I'm kind of bored I decided to wash my summer rims (15" original basketweaves, probably going to sell them). There was a lot of what appears to be grease all over sides and back, what's that for? I didn't remove all of it (just some spilled over the weaves) in case it's necessary, but what's it for? Is it just grease the wheel guy puts to ease the tire installation process?

Thanks