I wouldnt do it. Most of those bumpers are merely a place to store your sewage hose. They are not made of anything really structurally strong. Usually rated for 150 or less pounds. By the time you add the hitch, and the bike rack...plus the added bouncing that usually happens when a rig is going down the road you most likely will have the bumper fall off. Also every bike rack I have ever owned, will state in the small print the warranty is void, if attached to the back of an RV.