Energy Cost of Riding Bicycles with Shock Absorption Systems on a Flat Surface

Abstract

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.

Current Perspectives of Cross-Country Mountain Biking: Physiological and Mechanical Aspects, Evolution of Bikes, Accidents and Injuries

“…Exploring the metabolic and performance responses between HT and FS on a circuit that simulated the XC-MTB race conditions, Herrick et al [64] showed that, with similar oxygen consumption, the HT bike was faster than the FS Suspension is widely used within MTB, but the best suspension mode to achieve superior performance during off-road cycling has prompted a debate among athletes and coaches. Most of the athletes still prefer the HT, claiming that FS may be related to a possible energy loss due to small oscillatory movements during pedaling movements, mainly at higher PO and during climbing [55,63]. However, studies that compared both HT and FS showed controversial results regarding perceptive, physiological and performance responses [59,60,62,64].…”

Mountain Bike Rear Suspension Design: Utilizing a Magnetorheological Damper for Active Vibration Isolation and Performance

“…While full suspension bikes offer advantages, it has been suggested that they are less efficient than bikes with only a front suspension due to increased energy lost to damping in the rear shock. 2 Several studies in the literature have examined this research question, with varying results. [3][4][5] While full suspension bikes may be less efficient at transforming energy at the pedals into potential and kinetic energy of the bike, a substantial enhancement of rider comfort and control appears to offset these losses in mechanical efficiency so that the overall efficiency of the rider/bicycle system is not appreciably different between a full suspension design and a design with front suspension only.…”

A general approach for analysis and enhancement performance in mountain biking modality

“…Suspension is widely used within MTB, but the best suspension mode to achieve superior performance during off-road cycling has prompted a debate among athletes and coaches. Most of the athletes who still prefer the HT, claiming that FS may be related to a possible energy loss due to small oscillatory movements during pedaling movements, mainly at higher PO and during climbing (NIELENS; LEJEUNE, 2004LEJEUNE, , 2001. However, studies comparing both HT and FS showed controversial results regarding perceptive, physiological and performance responses (FAISS et al, 2007;HERRICK et al, 2011;NISHII;UMEMURA;KITAGAWA, 2004;SEIFERT et al, 1997).…”