There is a concurrent thread here called "bicycles" you might look at. I'm pasting from that here:
Just got this back from Hollywood:
info@hollywoodracks.com
Attachments
2:02 PM (1 hour ago)
to me
Hi Doug,
Travel trailers (including towed vehicles and fifth wheels*) have a slight side to side motion that's very low frequency (1 to 1-1/2 times per second) that fatigues the steel from which the racks are manufactured. The fatigue first happens at a molecular level, but eventually (several thousands of cycles later) a visible crack will appear. Once the crack has formed, it will enlarge, finally to the point where the rack drops off the vehicle and the rack (and bikes) impact the roadway. This is also a dangerous situation for whoever may be following the trailer on the highway. We have seen 100+ incidents where the consumers/end user has not taken this advice and suffered disastrous results. We've even had phone calls from consumers who said they read that advice (do not use on a trailer) and ignored it, only to discover a tragic end result. So, please don't do it.
For Class A,B,C, towed vehicles and fifth wheels our RV Rider is the only rack that will work. It will not work for travel trailers.
The RV Rider (HR1700) is a heavy duty version of the Sport Rider for Electric bike rack (HR1500). The key differences are attached.
Thank you,
Jen / Hollywood Racks