Well, I saw this set up a few years ago at the Indy RV show:

For what it's worth, I carried our bicycle for 2 from our Springdale bumper for 8 years. Never had a problem. I bungied it down so it would not wiggle.


Since then, my wife and I have pretty much given up the bicycle. I think we're just getting too old now. So on our current camper, it came with a re-inforced 1 and 1/2 inch receiver so I comfortably attached the same bumper bracket and now carry this. I had to do a little modification to keep it from rocking, but it works, and it's traveled thousands of miles now. Of course, the weight is not as much as 3 bicycles either.
I have heard of others having bumper failure on their trailers with too much weight from bicycles. If you take the time and have the bumper re-inforced or a receiver hitch installed, you might do well then. Check your welds. If they are spot welded, don't attach the bicycles. If they are solid welds, you might be able to.
Still.... over the tongue is really the best, if your tongue has room. My current camper does not.
