Any suggestions how to best clean those changes on the aluminum (Specialized Allez Epic, carbon fiber bike with aluminum lugs, early 90ties). I think it is due to some aluminum carbon contact or due to the aluminum carbon resin contact oxidation? I think I have have read somewhere it was somehow common in those type of bikes - is that correct? Any good cleaning advice? It does not wipe/polish off with steel wool!(Bike is still sturdy and solid otherwise)