Made two cross country trips with our 2013 Sanibel 3500 with a bike rack attached to the factory installed hitch. After our second trip, I noticed that the rack was excessively worn out. I called the manufacturer for replacement parts and was informed that this rack was not to be used on 5th wheels or trailers due to the excessive up/down movement of the units. They informed me that I was fortunate in not losing the bike/unit during my travels due to structural failure of the rack. I reread the instructions that came with the rack and sure enough there was a warning that stated, "Not to be used on any trailer, fifth wheel or towed vehicle" I ended up rebuilding the rack and selling it. Began researching and found that there are bike racks specifically designed for 5th wheel and trailer use. I since bought one, since wifey will not let me bring the bikes inside the unit.
I thought I would share this info, for I for one, did not read all the fine print and was lucky not to have dropped two bikes and rack on to traffic behind me during my travels.
BTCM(SW) Ret USN
2013 Sanibel 3500
2013 Ram Truck 3500 Laramie Longhorn Dually
2015 Days camping-185
2016 Days camping-238