I’ve carried, at one time, approximately seven times the worth of my camper in bicycles, on top of the pop up without fear of them flying off. We’ve now got a couple of thousand miles on the setup and it works perfectly. I only have $160 into it.
A couple of commenters asked for some better photos when I wrote my first post about how I built the rack, so here’s one that shows the routing of the straps to keep the rack where it belongs, from the side:
And one from the front:
Starting with the back strap, rather than mess around with gluing a channel on my camper for the rear wheels, I simply run a ratchet strap through the back wheels and that does just fine for keeping the rear wheels stable. That angled strap in the middle, runs from the front hitch area to behind the camper’s wheel, looping around the rack. One on each side, one goes over the rack and around and one goes beneath the rack and wraps around it… The idea is to have opposing forces that will keep the rack from sliding forward or back. Finally, I’ve got one last ratchet strap that side-to-side over the rack, which really firms everything up nicely.
The rack above will hold four bikes, anything from a single bike to a triple, depending on how far forward I attach the rack.
Legal Note: This post detailing a Quick and Easy Bike Rack is for your benefit. I assume no responsibility for anyone using what I did to build their own rack. Your bicycles and your carpentry knowledge, along with the installation of all tie-down straps and the proper use of the fork mounts are entirely your responsibility. Not only do you risk damage to your bikes, but other people and their property as well if you do something stupid, ignorant, incorrectly or try to skimp with cheap products. All responsibility for what you do falls on you. This post is expressly for informative purposes. If you do not possess the intelligence to build your own, you should absolutely buy a proper bike rack for your pop-up.
UPDATE: I added another post with better photos of the ratchet straps here.