Home Built Extreme Fat Tire Bicycle

Bike projects are awesome. And it doesn’t get more awesome than this: a home-designed and built mega-fat wheeled bike. Capable of traversing soft sand with great ease, this thing looks like it will take you just about anywhere.

This crazy vehicle was created by Instructable user marple200, who describes the project as a combination of wanting to design and build a bike, and to learn to weld. He handled both in one of the best ways ever.

The two big challenges with his design were creating forks to fit the oversized tires, and engineering a system to allow the chain to reach the gear outside of the tire. The wheels on this beast are from a Yamaha ATV, and the frame is pieced together from a existing bikes. The issue of the forks was created using some rigid electrical conduit pipe and scrap pieces of bike carrier racks found in a dumpster behind a bike store.

The drivetrain issue was sorted out in a pretty novel way: a jack shaft/transfer hub. The pedals drive a chain that is mounted to a raised gear behind the bike seat. The gear turns a spindle that stretches to the outside of the tire and is connected to a second gear on the rear wheel. All of the mounts are creatively sourced pieces of donor bicycles.

The write up is a good example of the capable and creative abilities of the bike’s inventor. It’s one of those projects that gives me that awesome inspired feeling to drop everything and get into my workshop. I’m itching to get that bike trailer sound system started…

Extreme Fat Tire Bicycle on Instructables.