An efficient optimum design procedure for bicycle rear derailleurs

Abstract

The rear derailleur on a multi-speed bicycle guides the running chain rapidly and precisely to a selected freewheel sprocket position without disengagement from the freewheel assembly. Therefore, the design of rear derailleurs is most important for designers. An efficient optimum design procedure for rear derailleurs is presented in this paper. Based on an established mathematical model, a series of optimum design sub-problems derived from the original optimum design problem are formulated and solved to meet all design requirements. The advantage of dividing the original design problem into several sub-problems is that it makes the upper/lower bounds of design variables in each sub-problem easier to determine. This reduces the trial-and-error efforts during iterative searching for optimum solutions. Thus, the design procedure becomes more rapid and efficient. It is worth emphasizing that the design procedure proposed herein is applicable to most known types of rear derailleurs.