Energy cost of riding bicycles with shock absorption systems on a flat surface.
Bike shock absorption systems reduce the energy variation induced by terrain irregularities, leading to a greater comfort. However, they may also induce an increase in energy expenditure for the rider. More specifically, cross-country racers claim that rear shock absorption systems generate significant energy loss. The energy losses caused by such systems may be divided in terrain-induced or rider-induced. This study aims at evaluating the rider-induced energy loss of modern suspended bicycles riding on a flat surface. Twelve experienced competitive racers underwent three multistage gradational tests (50 to 250 W) on a cross-country bicycle mounted on an electromagnetically braked cycle ergometer. Three different tests were performed on a fully suspended bike, front suspended and non-suspended bicycle, respectively. The suspension mode has no significant effect on VO2. The relative difference of VO2 between the front-suspended or full-suspended bike and the rigid bike reaches a non significant maximum of only 3%. The claims of many competitors who still prefer front shock absorption systems could be related to a possible significant energy loss that could be present at powers superior to 250 W or when they stand on the pedals. It could also be generated by terrain-induced energy loss.
Nielens
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Centre de médecine du sport, Cliniques universitaires Saint-Luc, Université catholique de Louvain, Brussels, Belgium. nielens@read.ucl.ac.be
Lejeune
T M
TM
D000328:Adult; D001642:Bicycling / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology*; D004867:Equipment Design; D016552:Ergometry / Q000295:instrumentation; D015444:Exercise / Q000502:physiology*; D006339:Heart Rate; D006801:Humans; D018482:Muscle, Skeletal / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology; D019876:Sports Equipment; D013314:Stress, Mechanical; D013499:Surface Properties