Joules sits on the back of a tandem bicycle and does all of the pedaling for both riders. He was created following a challenge to build a robot that pedals a bicycle like a person. The intent of Joules was to express the joy of design and craftsmanship, with practicality playing no role whatsoever. The electrically powered pedal driving mechanism was a particularly fun part of the design. His builder, Carl Morgan, says that Joules' top speed will never be known because of the abject cowardice of his human riding partner. Here is flash animation of Joules.