Take a closer look at the picture above, and you will observe that the ordinary seeming bike actually doesn’t have the ubiquitous chain mechanism. Ingeniously contrived by some students of the University of Pennsylvania, this fascinating prototype features an entirely chainless drive system that can be electronically switched between fixed gear drive and freewheel maneuvering.
Christened as the Alpha Bike, the contraption incorporates an advanced Switchable Integrated Free-Fixed Transmission (SWIFT) Drive system. This transmission mechanism was specifically designed by University of Pennsylvania Mechanical Engineering seniors Geoff Johnson, Lucas Hartman, Katie Savarise, Evan Dvorak, Katie Rohacz, with Dr. Jonathan Fiene as advisor. Basically the mechanism allows for the above mentioned electronic switch between fixed gear drive and freewheel.
The mechanism also manages to fuse some elements of an electric bike, like the front section consisting of a drum brake and dynamo. The dynamo provides the main power for the electronics, charging two super capacitors which in turn juices up a system of sensors and a micro-controller. Coming to the rear, there is a three-speed gear set which can be operated by a push-pull cable.
The custom made frame also exhibits a LCD display on the light weight (458 g) handlebars, which gives important information concerning time, distance, gears and even wheel speed. Though there is very little information on how the bike will itself perform in on-road conditions. But this remarkable conception was indeed declared the winner of Gemmil Award in the University’s 2011 Senior Design Competition, and as the designers mentioned that the intention for their concept was to:
…create a bicycle to push the boundaries of integrated systems.
Source: GizMag
