Originally Posted by mtkeg15
Did you look in to the rear bumper attachment? Made for 4 or 4.5 inch square bumpers- they clamp in and can hold 2 or 4 bikes. Just installed mine a week ago and was on sale and had good reviews. Mike
While the bike rack may be strong, the weak point is the structure (or LACK of structure) of the X17Z's bumper. It is a 2 x 4 C-Channel and, as stated before, is really only ornamental.
However, in general, light weight RV bumpers are not meant for 100+ pound loads (3 bikes + rack weight) with dynamic transport accelerations. We had a camping friend who arrived at their destination only to see their bumper and bikes gone -- where? They think it may have happened on the Mass Turnpike, but really had no idea. Imagine being the person behind them and finding that hunk of metal in the middle of the road.
Most folks think that if a trailer bumper can carry a spare tire, it can carry bikes. But the reality is that the bikes are projected further away from the bumper and the bumper experiences quite a bit of torsion loading due to the leverage (hence the weld cracks in the pictures below).
Unless the bumper is a truly structural member, the only real solution for carrying bikes on the rear of a trailer is to weld/bolt a trailer hitch directly to the frame. The bumper attachments are just not robust enough to carry the dynamic torsional load.
Check out these pictures of a failed 4x4 bumper: