I was wondering that looking at the photo and thinking "Hmm, would you steer or counter-steer that thing?"
Y'know how wider rear tires can kinda make your bike handle a little weird? Take that to a 4' wide tire and put 'em front and back. Not the best plan for geometry. Gotta say though, the way they mated that moto disc and caliper for a really functional brake was way cool. Though they came up just short and ran out of coasting speed toward the end and had to push it the last few feet, they got a big round of applause when they crossed the finish line.
Scott