I just finished some modifications on my Salem Cruise Lite 221 RBXL rear bumper. I wanted to carry two 20" mountain bikes but as every one knows these bumpers are a little weak. So I decided to enhance the horrible mounting that the factory did. I used 1 1/2" x 1/8" flat bar to strap the top of the frame to the bumper. Then I welded 2" x 1/4" angle to the frame and the bottom of the bumper. Now the bumper is held securely and should be able to hold two 24 pound bikes.