Dimensions are not critical. They were based on what was in my shop at the time and the size of my tool pouch. I started with 6.25" of tubing and 6.25" length of all-thread stock. Stock is 1/2 - 13 thread and tubing is 5/8" OD and just over 1/2" ID. I made a wing-nut from 1/4" brass, about 4" long. A common nut for which you have a wrench in tool kit could be used. I made a foot and saddle from aluminum scrap on hand. The foot could be a short bolt with large head, such as an "elevator screw" used for leveling tools, refrigerators, etc. The saddle could be a hex nut to fit threaded stock with a notch cut in top with bench grinder, hacksaw, or the like, and fixed to top of threaded stock with a drop of Locktite or epoxy. You just need something to keep it in place without damaging paint. I went the route I did because I have a lathe and mill in the backyard. If you need to remove tire from sidecar or bike it is very handy. I have even used it to make slight adjustments in sidecar alignment. It can slightly spread sidecar frame from bike frame. If the frames need to be pulled together slightly, loop a 3/8" rope around them, tie, and put tube through rope and twist. This is much more controlable than a bump with the hip. GA-DK