THREE PURDUE UNIVERSITY industrial designers who tapped into memories of their own childhood cycling misadventures have built a bike that ditches the training wheels but keeps rookies stable. Called SHIFT, it slowly transforms from a tricycle to bicycle configuration as the rider pedals faster, then returns to trike formation as the rider slows down. If I had one of these years ago, I wouldn't have a scar on my right knee.
From the Associated Press:
Lead designer Scott Shim hopes the design, which won top honors recently at an international bicycle design competition, can help children slowly gain the skill and courage to pedal off on their own.
The design features a single front wheel and two slim rear wheels that are initially splayed outward to stabilize and prevent the rider from toppling over. As the rider accelerates and leans forward, the rear wheels shift inward, narrowing into a single wheel surface that essentially makes it a two-wheel venture. As the bike slows, the rear wheels tilt back to the tricycle formation.
Rick Callahan -- "New Design Could Transform 1st Bike Ride"