After getting inspired by the final episode of American Choppers and then seeing my neighbors driving around on their snowmobiles, I set out to make a crazy combination of the two as a pedal-powered monstrosity. I designed and constructed this bike in just under three weeks using three broken bikes, some steel tubing and angle iron, and an old 1990 Polaris snowmobile track.
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
After getting all the necessary tools, parts and as many bikes as possible, start by planning out how to integrate the snowmobile track with the bike frames. Children’s mountain bikes with 20” tires fit nicely inside of the track, and the knobby mountain bike tires fit snugly in the gap where the sprockets are supposed to fit. I found that the limited space inside of the tread accommodated a three wheel configuration more easily than all four wheels.
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.