This paper provides measurements of rider-induced loads during standing cycling. Two strain gauge dynamometers were used to measure these loads while three subjects rode bicycles on a large motorized treadmill; the cycling situation simulated hill climbing while standing. Comparing the results to those previously published for seated cycling revealed that the loading for standing cycling differed fundamentally from that for seated cycling in certain key respects. One respect was that the maximum magnitude normal pedal force reached substantially higher values, exceeding the weight of the subject, and the phase occurred later in the crank cycle. Another respect was that the direction of the handlebar forces alternated indicating that the arms pulled up and back during the power stroke of the corresponding leg and pushed down and forward during the upstroke. Inasmuch as these forces were coordinated (i.e., in phase) with the leaning of the bicycle, the arms developed positive power.
Cal Stone is with Hewlett-Packard, 1212 Valley House Dr., Rohnert Park, CA 94928-4999. Maury L. Hull is with the Department of Mechanical Engineering, University of California, Davis, CA 95616. Direct correspondence to Maury L. Hull.