Design of a robotic rig for testing bicycle transmissions

Human testing of bicycle equipment can be subjective. It is often more desirable to establish objective measures of a system´s performance. A bicycle transmission must withstand varying loads placed upon it by the rider and the riding conditions. It must also reliably shift between speeds through numerous cycles. This paper describes the design of a robotic rig for testing bicycle transmissions. The test rig simulates the pedaling and shifting of a human and allows for programmed resistance to simulate riding conditions. The test rig can be programmed to perform numerous shifting sequences under varied operating conditions for tests lasting several hours. Shifts can be performed every 1.5 seconds to accelerate the lifecycle of the transmission. This paper describes each of the systems of the test rig and highlights the design considerations in its development.