Take one look at the front fork of this dirt bike and you’ll notice that it’s not really a front fork at all. A custom front end replaces the traditional design in order to give this motorcycle all wheel drive. Look closely and you’ll see the chain that drives the front wheel. The swing-arm like addition lets the front end retain all of its suspension and steering and that’s where the project gets tricky.
We actually saw this thing in person at the monthly meeting of our local hackerspace: Sector67. [Martin Lawson] got his seven minutes of fame during the presentations (they use a prototype of this scoreboard to limit each presenter), and then was mobbed with a ton of interest afterwards. We were able to get a pretty good look at how the front drive works. It starts with an additional cog fastened beside the one that drives the chain for the back end. This feeds up through some tensioners and transfers out on the left side (from the rider’s perspective) of the front end. From here the rotational force is transferred to the right right and includes a U-joint to account for steering. The last chain goes straight down to the wheel.
The idea is that when the rear wheel loses traction you’re still being pulled by the front. This is illustrated well in the video after the break. [Marty] — who has a patent on the design — is trying to get some interest from manufacturers. He says the ability ride right through poor traction terrain make this a lot easier than a traditional dirt bike for beginners to ride. But it’s obvious the professionals are having fun on the thing as well!