Since the tubes on this frame are aluminum, The 4 U-bolts that are now holding the shock-mount plate are placed over two saddles made from a short length of steel pipe sliced along its length, to spread out the force so they wouldnÃ¢â‚¬â„¢t crimp the tubes.
If I couldnÃ¢â‚¬â„¢t find steel pipe that was the best ID to snugly fit over the frame tubing, I would have gotten slightly larger diameter pipe and filled the void with JB-Weld (metal epoxy). I wouldÃ¢â‚¬â„¢ve rough-sanded the inside of the pipe to help adhesion, and rubbed Chapstick (or any other convenient waxy substance) on the frame to prevent it from sticking to the frame.
The all-thread rod is now passing through a Brass Pipe T with three Â½Ã¢â‚¬Â threaded holes. I installed a brass bushing into the center Â½Ã¢â‚¬Â hole (actually about Â¾Ã¢â‚¬Â ID, as Â½Ã¢â‚¬Â refers to the ID of the intended plumbing pipe diameter), and this bushing is a Â½Ã¢â‚¬Â OD to 3/8Ã¢â‚¬Â ID. I bought a Â½Ã¢â‚¬Â-13 tap, and re-threaded the bushing ID so that the all-thread rod fits snugly. The bottom of the T simply has a snug hole drilled through it.
The two smaller central U-bolts are placed around two 1/2Ã¢â‚¬Â pipe plugs that are threaded into the brass T. The common cast roundish brass T's would've worked fine, but when I saw the squarish billet brass T's, I felt they were a little stronger
If this brass T seems to work well enough, I may fill it with JB-Weld. In my opinion, the aluminum plate and brass T only hold the rod in proper alignment, and probably will not see much in the way of side loads. The neck of the shackle has been reinforced with an all-thread-coupler which looks like a long nut.
At the bottom of the threaded rod is another 1/2" to 3/8" bushing (re-tapped to 1/2"-13 threads) and a common cast brass T with all three ports having 1/2" pipe thread. Brass can be drilled, tapped, and cut with a hacksaw fairly easy, while still being stronger than aluminum,...plus I like how brass looks (Ex-Navy bubble-head). The brass T was hacksaw-cut and file-shaped to fit in the crotch of the chainstays.
Acquired a 4" plastic clothesline pulley from Home Depot ($5) that is a perfect fit over a bike chain, and a $5 used thrift store inline skate set with 10 wheels/bearings total...Thanks AW and torker!
If this shock mount works well, IÃ¢â‚¬â„¢ll make up something that looks better after I resolve the rest the issues and the bike is functioning. Ã¢â‚¬Å“When youÃ¢â‚¬â„¢re trained to use a hammer, everything looks like a nailÃ¢â‚¬Â