I think it is a good idea to bring this topic back up, this time of year. The square tube "so called" bumpers are for decoration and to carry the sewer hose. Thats about it. I carried the spare tire there for a while, as the manufacture had indicated, but noticed some cracking where it (bumper) was attached to the frame. I moved the spare to a location up under the front storage area on my 5er. I then had a pro welder put on the 2" hitch and reinforced to the frame. I use one of those hitch baskets to carry my 4k generator (107 lbs). I am like you all, I have seen so many attach bikes, generators, patio chairs, and etc bouncing pretty bad and it was only attaced to the bumper. This is one thing I do like about rear cameras. If positioned correctly you can see if there is a problem rising from the weight on the square tube and a bumpy road.

 

I love my home made flat bike rack, that slides right in the hitch, and theres a big bolt on the side you tight on the side of the hitch, keeps it from moving/bouncing around.

Very very solid rack!

 

This is my bike rack:

I removed the factory sewer hose holder ("bumper") and used 3"/.25" square tube with 3/8" welded brackets bolted to the trailer frame. 2300 miles and no issues what so ever, even over I80 through the Sierras. CA. really needs to fix that pavement up there!

 

I put a bumper 2" hitch on my 5er and when I got back from a 600 mile trip I had to straighten the bumper. Took it to a buddy of mine and he welded it back on and put some reinforcement plates on top of the bumper to the frame. We next put a class 3 hitch on the back of my 5er and no problems since.

 

good to know...will fab one to frame, just to be sure. WILL59