Trek Lime

I purchased a Trek Lime for my wife. It is a great bike for the non-techie bicyclists. She didn't like to shift gears and the Lime was the perfect bike. The Lime has a dynamo in the front hub which charges the shift box located under the bottom bracket. The shift box is connected to the three speed rear hub via cable. The shift box has a sensitivity setting for shifting points. When you pedal the shift box charges and shifts the rear hub when you reach certain speeds.

Trek Lime site