Via: Doug Malewick
"Doug Malewicki was the designer and engineer of Evel Knievel's steam rocket powered SkyCycle X-1 canyon jumping motorcycle. Theoretically - a two wheeled, streamlined, fin stabilized rocket that is capable of rolling along on those wheels could be deemed a "Motorcycle". Similarly, launching and flying across the Snake River Canyon could also be deemed a "jump". Poised here for action is the model of the canyon jumping X-1 Skycycle "Motorcycle" Malewicki designed for famous daredevil Evel Knievel in the early 1970's."
"Malewicki is shown here shaking hands with Evel at the machine's unveiling at the Twin Falls, Idaho Snake River Canyon jump site on May 6, 1972. On the left is Robert Truax who invented and holds the patents on Steam Rocket engines. In the background wearing sunglasses is Facundo Campoy, one of Truax's partners."