Does anyone have any tips for preventing rust and keeping a steel frame in top condition? My frame is relatively new (two years old) and in pretty good shape, but it's beginning to get somewhat chipped on the down tube and bottom bracket. From the looks of things, the chips aren't down to bare metal, but they seem to have taken off the shiny top coat of paint. These are all tiny little specks from rocks being thrown up, much like you find on a car's hood after a lot of highway driving. I figure my best bet is to clean the tube really well and then dab clear nail polish on the spots, but this won't leave a very smooth finish. Any better ideas?