I really enjoy seeing the things that you all have come up with and built so decided to show one of my contraptions. Here's a two-wheeled tractor that I made several years ago, named "Rube" for Rube Goldberg. I don't have a good picture from the side that would show the mechanics better, but power went through a triple pulley to a three-speed transmission from a 4wd Chevy Blazer. The rear of the tranny was attached directly to the input of a gear reduction box from a David Bradley two-wheeled tractor that had been turned sideways. The axle shafts from the DB box were cut off and the one running toward the front of the tractor was mated to a cutdown rearend from a '75 Chevy Nova that had been turned backwards. By turning the brake backing plates backwards on the Nova rearend, I was able to use the emergency brake cables to rig up independent brakes. First gear reduction was around 100:1. With antifreeze loaded in the 14" tractor tires, it was practically unstoppable. I used it primarily for pulling a cart built just for the tractor with a seat on it and an articulated hitch to keep the unit together. I disassembled Rube later to use some of the parts in other projects.