An analytical model to study the radial stiffness and spoke load distribution in a modern racing bicycle wheel

Abstract

A theoretical study has been carried out to analyse the behaviour of the structural components used with a modern spoked bicycle wheel when loaded at the hub axle and supported at the rim. The work has involved developing some general equations for calculating the contributions which the axially loaded spokes and the bending flexure of the rim make to hub displacement and hence hub-to-rim wheel stiffness. The work considers the effect which the spoke tightening preload has on the distribution of load throughout the wheel and also the influence it has on wheel stiffness. The developed theory has been applied to some modern racing cycle wheels which have just a few spokes and use a relatively rigid, part tubular cross-section rim. Such designs are evaluated, using actual mechanical properties, and their behaviour is discussed against more traditional multi-spoke wheel designs which have relatively much more flexible rims. The theory has been compared with the results obtained from experimentally load testing a bicycle wheel using 12 and 18 spoke variants.