I too am working on an ST3 right now. I am using 930 CVs and 19.25 inch axles instead of the u-joints. I also am using 1.25 OD .109 tubing for the frame instead of the 1" black pipe the plans call for. I have a CB750 engine I am pulling out of my old mini buggy for power. I was a little disappointed with the ST3 plans as they left out some dimensions and didn't even include a bill of materials. How much steel did you use for the frame. I already bought 260 feet of tubing and I think that should be enough for the fram and chassis. I modified the suspension a great deal to move the pivot points closer to the center of the chassis for an arm length of about 20 inches. I am also going to put some miata rotors on the front wheels for more breaking as I intend to ride mostly on desert/trails with it. How much room do you have for the engine? The plans for the engine box are somewhat smaller that my older buggy but I don't want to extend the frame past 10 feet. Are you going to mount the engine on top of the rear carrier? I am going to do that but need to get an offset sprocket in order to do so with the CB750F engine. Good luck on your build. There aren't many ST3 builders on here so keep posting. As soon as I finish finals I should be able to put the frame together after christmas break.
