Feb. 18, 2009 — The next time you change a bike tire, think about upgrading your power as well. Scientists at MIT are testing a new power generation, storage and propulsion system known as the GreenWheel that will turn any pedal bicycle into an electric hog.
“Just take the wheel off, put a GreenWheel equipped wheel on in its place, plug it in and it should work just fine,” said Ryan Chin, one of the GreenWheel designers. “The whole thing has been designed so all the parts except the throttle are enclosed in the wheel.”
From the outside, the GreenWheel has the radius of a small dinner plate and is about 2 inches thick. Inside the aluminum frame sits the three major GreenWheel components: an electric generator, batteries and an electric motor.
For now, installing GreenWheel on your own does require a moderate level of technical knowledge or a trip to a bike shop. The GreenWheel can be installed on any bike frame or wheel size, but the original spokes have to be replaced with shorter spokes. Michael Chia-Liang Lin, a master’s student at MIT developing the GreenWheel, called his parents in Taiwan, who own a bike shop, to figure out how to respoke the wheel.
Under its current configuration, a bike powered solely by a single GreenWheel (front, rear or both wheel can be equipped with a GreenWheel) has an estimated range of 25 miles. Pedaling the bike doubles the range under electric power, provided the rider isn’t traveling at the nearly top speed of 30 miles an hour. The bike can be charged by pedaling or by plugging it into the electric grid.