I have to repaint my Yakima ski racks after each season. The original paint started peeling off with the slush and ice at the car wash. I doubt if Yakima ever used a proper primer. That being said, I just buff the surface , clean, degrease, and repaint with a rattle can. I mask off everything not being painted of course. They are flat black so it was easy to match. Comes out looking pretty good but doesn't last more than a season usually. Ice and slush freezes to the paint and in the carwash the ice pulls the paint. Bike rack shouldn't have that problem so rattlecan job should last a long time.