The robotic bike test rig simulates the human pedaling and shifting and also applies resistance to the rear tire to simulate various riding conditions. As you can see, the robot does not look like a human. At the pedals a 1 hp motor actuates a linkage to recreate the variation of torque that the legs produce on each stroke. The shifting cables are connected to screw drives and the positions measured by optical encoders to accurately shift speeds. The rear bike wheel spins a drum that drives another 1 hp motor where the resistance is varied by controlling the voltage on the motor. The output motor set up like this acts as a generator so we dump the electricity into a series fo lightbulbs under the rig. All of this is automatically controlled by the computer.

With this rig we can test the bicycle for several consecutive hours shifting every two seconds. That allows us to drastically accelerate the life of the transmission for testing.