So I was lying in bed the other night trying to come up with ways to add rear suspension to a two seater Murray kart. Not having a bender and not wanting to spend money buying one I had to get a little creative so I started thinking about how the rear suspension is set up on my Mustang. It’s basically a 4-link with upper and lower control arms. Very basic but also very functional and strong, so back to my design idea and lack of equipment for bending round stock. Could one use something like the front fork from an electric scooter or small bike to make a control arm. Basically, cut the frame right behind the seat. Slide the forks into the frame, one on each side. Weld some round bar on each end of the fork where the tire would normally mount and then use bushings. Take the other part of the frame that was cut, weld some tubing so that it can slide between the forks and then run a bolt thru all of it. Weld up some shock mounts and mount the shocks. I pulled a picture from an electric scooter to give everyone a better visual. It might be a little small to handle the load but wouldn’t forks from a small bike be just fine?
Think of replacing the area of the shock that you mount the tire to with 1" length of pipe welded horizontal to both down tubs of the forks and then a pipe welded on the frame that can slip between the down tubs of the forks and be bolted up.