The Fat Tire Sand Bike designed by Mike Scarani, is a 21-speed, rear drive sand cruiser that uses disc brakes and an offset jack shaft to make the soft sand a bit more bearable to navigate. He designed it using no 3D CAD of any sort, but his knowledge based in mountain biking, architecture and a few CAD applications, gave him just enough passion to push the limits of drive train dominance. The layout was done on a piece of cardboard:
I did not use any CAD program even though I have some experience with CAD programs. I did all my initial design by hand sketches and then final layout on the cardboard. The primary reason, I guess, is that it was a fluid process. I did not know all of the components I was going to use at the start of the actual construction. I had a general idea, but you can see by some of the earlier photos how the overall frame design changed.