Here's more pics of storage tube.
Backside cable attach to frame
front side cable attach and tighten location.
Saddle blocks on both sides between frame and tube.
I used 1/4" aircraft cable with 2" wide stainless bands between cable and tube so cable would not bite into tube.
To purchase end caps from plumbing supply company proved to be to expensive so I made my own out of white plexiglass and wood.