The Design of Variable-Ratio Chain Drives for Bicycles and Ergometers—Application to a Maximum Power Bicycle Drive

Abstract

This paper describes a technique for generating a chain drive capable of allowing a desired varying angular velocity function on the driving shaft while maintaining constant angular velocity of the driven shaft. The technique is closely related to the synthesis of cams with flat faced oscillating followers. The technique is illustrated by the synthesis of a drive train for increasing the power applied to the rear wheel of a bicycle. The synthesized drive train shows a theoretical 12.6 percent increase in delivered power. Comparisons with published experimental results, as well as a discussion of the assumptions used in the synthesis procedure are included.