Well, if they're anything like the roofs on a 53' Dry Van, I'd build a solid structure inside the cargo area....so, might as well pull it out and use that instead of the truck. I had to climb on my trailer, to tape up a hole..and did so gingerly, trying to place most of my weight on the wall and cross beams. May have actually caused more damage in the process. You can get away with reinforcing it for bikes, I'm sure...but I'd use all that valuable space, to haul up a separate viewing platform.
anything worth doing is worth overdoing..