Lastly, I shall show a couple of different systems tried by Jim and I to provide differential action on Trucks that where either missing the original drives, or in my case, on my tribute bike.
On the orange bike, Jim used a differential from a ride-on lawn mower and attached a pulley to it. He said it works well.
On the maroon bike, Jim took a different tack and used variable pulleys from a minibike style torque converter on the outboard ends of a solid drive shaft to provide slippage. I have seen this operate, and while it works to move the truck, it leaves a lot of slop in the belts. What Jim was trying to replicate was the factory style clutch action.
On my replica, the last one pictured, I took the Simplex idea of outboard clutches and used modern pulley clutches. To accomplish this, I called Max-Torque, and had them build me clutches with very light weight springs, so they engage at 400 rpm. This allows them to freewheel in turns when not on the throttle, yet lock up at low rpm to just crawl along. I also have used a torque converter drive from the Honda clone motor, and this truck can really get up and go!
