World’s Fastest Dirt Bike There is No Stopping the Cardboard Robot KX500 The Cardboard Robot KX500 is the World’s Fastest Dirt Bike! On September 6th 2008, Kevin Kilkenny exited the timed mile at the Bonneville Salt Flats, USA at 130.418 miles per hour. He turned the bike around and rode back across the same stretch of real estate at 132.444 m.p.h. Setting a new record average of 131. [ ... ]