It’s a fun challenge recycling old bike parts and converting them into a new bike, and this massive, 7 foot long bike provided some unique challenges. Integrating the tread with the bike frames and turning through a big track on a heavy bike that doesn’t allow for traditional high-speed steering is definitely an adventure.
A MIG welder and a regular hacksaw served as the primary tools for construction, in addition to a common set of wrenches and screwdrivers. This is definitely a great project for diy bike or snowmobile enthusiasts with some junk bikes, scrap material, and free time.
Step 1: Planning the Internal Frame
Start by disassembling the two bikes for the interior assembly down to just the frame with the pedals. Cut down the frames so that they fit inside the track with enough clearance for it to rotate. The frames will be kept parallel with the addition of the third wheel between them in the back. Center the third wheel down the middle of the track by welding the seat and chain stays from an additional bike frame to the inside of the other bike frames, giving another set of dropouts where the wheel could conveniently be attached. When welding to the bike frames, make sure to sand or grind all of the paint off of the surface of the metal. The dropouts on the third wheel also make it easier to remove the tread by just taking off that third wheel first. *Be sure to dimension the assembly so that the track is snug with deflated tires so that once you inflate the wheels, the track will be tight without having any other mechanism to tension it.