Since camping season has slowed down, I finally have time to share my design of a heavy duty hitch receiver on the rear of my T12RBST Hardside. (Same as the Rockwood A122 Series)
My purpose was to allow me to safely carry a 300 lb. motorcycle on a 40 lb. hitch carrier. I needed a 2 inch square receiver, since that's what comes with the carrier.
Clearly the flimsy rear bumper was not an option as an attachment point. Using the heavy rearmost cross beam, as well a 2 smaller cross beams forward of it seemed to offer more than sufficient strength. Here is a shot of the completed installation. (I had just washed the bottom of the camper, so a lot of water drops are there)
The 1/4 inch thick, 5X5 angle iron is 18" wide. A 1/4" by 4" by 18" flat pate is on the other side of the trailer cross beam, and solidly bolted to "sandwich" the cross beam. If you look carefully, you will see two gold colored bolts below the square tube going forward. Those go through the smaller cross beams, and are backed with 2" angle iron to sandwich the beams.
This shows the receiver stub welded to the large angle iron, and an adapter made of another stub welded to a standard ball mount. This was needed to raise the point of attachment for the carrier to be above the bumper. Due to an error in my measurements, the assembly came out 1/2" too low, so I had to bend the top of the bumper.
Side and rear views with the carrier installed.
Note that instead of using standard hitch pins, I used 5/8" bolts, washer, and nuts to secure the adapters. This reduces the slop in the connection to zero.
I have put over 5000 miles on this with no problems. Note that I carry a 135 lb. generator and some heavy tools in the front of the camper to balance out the weight. The total weight of the camper is now 3000 lbs. and I have a tongue weight of 340 lbs.
Loaded up and headed NORTH for the Summer