Wait, do you see it? Here, let me help:
Yep, that's an ordinary cordless drill that Instructables member BooKooDesigns has put inside this mini bike to make it go vroom!
He reports:
This bike can reach about 35mph on a fully charged I-on battery. It will also turn peoples heads when you zip past them riding on a drill. This bike can fit Rigid, Makita, Dewalt, Ryobi, etc. A drill with about 1700 to 2000+ rpm is ideal to get this bike moving. Overall this bike is a great, fun to ride and handles great.
[link]
A not-so-cool looking but functional alternative with likely much better range can be purchased for $220: http://www.amazon.com/Razor-E300S/dp/B0085HM3VE/