I know that there is a lot of heated discussion about putting bikes on the back bumper, usually swirling around discussions about adding in a tow hitch and then attaching to that.
That being said, I have two "other" ways I wanted to see if anyone had done and if they had success or issues.
1 - A multi-piece bracket on the bumper. I came across this on Amazon today, it is two piece set, one for the front wheels and one for the back wheels, and the attach to the bumper directly with U bolts on the left and right side. I do not think that the U-bolts would crush the bumper, but it does say "Bumper Bike Rack attaches to a 4" -4.5" RV bumper with a 6.5" U-Bolt". What I like about this option, if it works is that I can try to center things so that each of the brackets is close to where the bumper attaches to the frame.
(I have not tried this myself, and I do not even know if there is enough clearance for the spare tire. There is also a 4-bike version). Here is the Amazon Link: http://smile.amazon.com/dp/B002MGFKNW?psc=1
2 - There are a lot of bike racks that are designed to attach to the trunk of a car. They usually have some sort of frame that sits against the car and some arms coming off. Has anyone tried attaching something like this to the bunk ends. the clips for attaching are usually just sort of a hook, and I think that they could get into the top edge of the bunk. I would just be worried about damaging the rubber gasket on the bunk end. Also I do not know if the latches are designed to take that much force pulling out on the bunk ends during travel.
Just trying to think outside the box, since the normal solutions are not great for these trailers but I really need to find a nice place to put my bikes during travel, I hate having them on the back of my TV and would love to put them someplace else.
Thanks for your thoughts. If you have tried one of these two options, if you have pictures, that would be great to see.