Just to add to this discussion, a couple years ago, we had a receiver professionally welded to the frame of our pop-up. We used a bike rack similar to this (
http://www.amazon.com/Thule-956-Parkway-4-Bike-Receiver/dp/B000CQ47GU/ref=sr_1_5?ie=UTF8&qid=1372338818&sr=8-5&keywords=4-bike+rack) but not that exact model. Anyway, on one trip we arrived to find that the bars had bent down and the bikes had all smashed together, dangerously hanging on for dear life by the straps we had secured them with. Now this type of rack is made for 4 bikes, but perhaps not as much weight as we had on it. Who knows. But it was a scary situation and could have been MUCH worse.
So we searched around for a new bike rack. Looking for more the platform type, like this one (
http://www.amazon.com/Hollywood-Racks-HR1400-Platform-Receiver/dp/B000QJC4AY/ref=sr_1_13?ie=UTF8&qid=1372338988&sr=8-13&keywords=4-bike+rack). In doing our research, we had contacted Hollywood Racks to ask a question, and this is the response we got:
However, all of
that may be useless information because our racks are not approved for use on
the back of any trailer or trailered vehicle (which includes pop-up
campers). Unless the pop-up camper is not a trailer . . .</span>
As follows is our explanation regarding why we do not allow our racks to be
attached to trailers:TRAILERED VEHICLE ISSUES</span></span>
Any trailer or
trailered vehicle (including 5th wheel type) has 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.</span>
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.</span>
We have seen 100+ incidents where the consumers/end user has not taken this
advice and suffered disastrous results.</span>
I'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.</span>
So . . . don't do it. If you insist on doing it regardless of the above,
please use some other companies’ rack.</span></span></span>
Best Regards,</span>
Rick / Hollywood Racks</span></span></span>I'd always been nervous about having the bikes back there. Freaks me out that they bounce around and we cannot see them. But now I've vowed to never carry them in this way again. It's just too big a risk for us and for anyone following us.</span>I do know, though, that there are plenty of different set-ups and ways to carry bikes very safely. This was just our personal experience. A bumper mount might be a good solution! I'm not judging...just saying that this scared the hell out of me. For now, we're putting the bikes in the bed of the truck and just sacrificing that space. We don't always take them anyway, but it's much easier to just remove the front wheels and secure 2 bikes to each side of the bed of the truck.</span>