Looking for a carrier for 1 or 2 fat tire e-bikes (65lbs. each) to install on the back bumber of our camping trailer. Rear bumper is 4” continuous welded square tubing and I would like to clamp around and, if needed, go under to the frame rails. I would not want to drill into it as it stores the septic dump hose inside. Anybody have something that works? The other option might be to mount a 2” receiver to the frame rails and the use a hitch carrier, but I was looking for a more economical solution. Thanks for any thoughts you can share.