Bicycle-Wheel Spoke Patterns and Spoke Fatigue

Abstract

The radial, lateral, and tangential stiffness of spoked bicycle wheels depends upon the rim's bending inertia, torsional inertia, the spoke sizes, and the spoke geometry. The spokes of three rear bicycle wheels of different spoke patterns were instrumented with strain gauges in order to investigate the effect of the spoke pattern on the spoke strain and fatigue resistance properties of the wheels. Spoke strains due to radial loads were measured in the laboratory. Time records of the strain of a right pulling spoke were collected from each of the wheels under actual riding conditions. Analytical, numerical, laboratory, and field studies show that spoke strains due to radial loads and in service conditions are insensitive to the spoke pattern. Small variations in the spoke strains between the wheels in the road tests can be attributed to variations in the loads, but do not significantly affect the fatigue life of the wheels.