Wednesday, November 22, 2006

The 2WS/2WD experimental recumbent

In theory, a 2 wheel steering bike could enter and exit corners harder. Several years were spent designing a 2 wheel steering "kneeler" type bike until I saw a Ryan recumbent bike sitting in a bicycle shop in 1998. That struck me as the perfect configuration for a 2 wheel steering racer. But rather than spend a lot of money making a high powered one with no prior art available to depend on, I built a lightweight electric one to test 2 wheel steering stability and control. It has 3 12v batteries, 2 800w Heinzmann hubs, and a Curtis 1204-001 speed controller. It was finished in early 2002. The steering has a 2 axis control - moving the stick left steers the front wheel right - which causes the bike to roll to the left - just like an airplane. The rear steering is proportional to the front - with the stick forwards, the rear steering angle was 50% of the front in the same direction - and with the stick aft, the rear steering angle was 50% of the front in the opposite direction. The proportion was completely variable with no rear steering at all when the stick is centered. The speed control and brake lever is also on the control stick. The second to last picture was taken at a recumbent bicycle rally in Arvada, CO, back in 2004. The bike is currently hanging from my living room ceiling after several hundred miles of successful testing.

Photo 3: Peter Forss