Lots of good info; I decided to build a roller system out of PVC with the load bearing down on the bumper. Lucky that my Traverse has a bumper! I did try a Malone Telos, but this unit didn’t work well for me, due to some medical issues of the user. Thanks for all the advice!
Be sure to use heavy enough PVC. PVC can become very flexible in hot weather. Heating PVC pipe is a common way to make bends where a fitting is not desirable. Again in very cold weather it becomes very brittle. Sch. 40 1½" will probably work for a short span.
Thanks , that is the size I’m using. I’m also inserting wood dowels in the higher stress areas