I would not mount anything on the back bumper of an Airstream. Its basic
physics as you run over rough roads, hit pot holes etc the amount of force
on the back bumper is multiplied exponently on the rear of the trailer -
doesn't matter if bolted to frame, bumper or what ever. Read previous
postings of things mounted on the rear bumper and causing frame seperation
- even on trailers that are not commonly known for frame problems.
My question is why would you want mount them way back there - where the
bikes will get all the dirt and junk that comes off the car and the
trailer, when you could carry them on top of your vehicle where they stay
fairly clean. Buy a good Yakama or Thule rack - your bikes will be much
safer and happier.
Ken Johansen
5358
Bike rider for 40+ years.