February 24, 2009 A fully self contained bicycle hub motor known as the GreenWheel has been developed by students at MIT that contains the motor, batteries and motor controller all within the hub enclosure. Very similar in concept to the E+ we reported on earlier this week (which we have been informed by a reader is a reincarnation of a Wavecrest Electric bike), but taken one step further by combining the batteries together with the motor in a single hub instead of putting the batteries in the front hub and motor/controller in the rear hub as on the E+.

The only external part of the GreenWheel system is the handlebar-mounted throttle that is connected wirelessly to the electric motor in the wheel, so absolutely now external wiring is required along the bike frame. The hub motor is spoked into a standard bicycle wheel and is powered by Lithium ion Nanophosphate batteries supplied by another MIT firm A123 Systems.

The potential advantage of this enclosed system is that if you want to give your bike an electric boost, you only need to change the wheel, not purchase a whole new steed.

No details on motor power output or battery capacity have been made available but range is expected to be an estimated 25 miles (40 km). 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 (48 kmh). The bike can be charged by pedaling or by plugging it into the electric grid. A123 batteries can be fully charged in only 10-15 mins.

Both front, rear or both wheels on any bicycle can be powered with a GreenWheel and the team estimates its range at 40,000 miles (64,000 km), or about eight years work of travel at an estimated 20 miles (32 km) per business day.

Paul Evans

Via Treehugger via Discovery Channel.