Comparing cycling world hour records, 1967-1996: Modeling with empirical data

University of Colorado Colorado Springs, Colorado Springs, Colorado, United States
Medicine &amp Science in Sports &amp Exercise (Impact Factor: 3.98). 12/1999; 31(11):1665-76. DOI: 10.1097/00005768-199911000-00025
Source: PubMed

ABSTRACT The world hour record in cycling has increased dramatically in recent years. The present study was designed to compare the performances of former/current record holders, after adjusting for differences in aerodynamic equipment and altitude. Additionally, we sought to determine the ideal elevation for future hour record attempts.
The first step was constructing a mathematical model to predict power requirements of track cycling. The model was based on empirical data from wind-tunnel tests, the relationship of body size to frontal surface area, and field power measurements using a crank dynamometer (SRM). The model agreed reasonably well with actual measurements of power output on elite cyclists. Subsequently, the effects of altitude on maximal aerobic power were estimated from published research studies of elite athletes. This information was combined with the power requirement equation to predict what each cyclist's power output would have been at sea level. This allowed us to estimate the distance that each rider could have covered using state-of-the-art equipment at sea level. According to these calculations, when racing under equivalent conditions, Rominger would be first, Boardman second, Merckx third, and Indurain fourth. In addition, about 60% of the increase in hour record distances since Bracke's record (1967) have come from advances in technology and 40% from physiological improvements.
To break the current world hour record, field measurements and the model indicate that a cyclist would have to deliver over 440 W for 1 h at sea level, or correspondingly less at altitude. The optimal elevation for future hour record attempts is predicted to be about 2500 m for acclimatized riders and 2000 m for unacclimatized riders.

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    • "This has resulted in a dramatic increase in the speeds reached from the 1974, 200m speed record of 69.23km/h to the present record which stands at 133.284km/h. Chester Kyle performed some of the most notable research on the aerodynamic design for cycling during some 4 decades [3] [4] [5] [6]. Most record breaking human powered vehicle concepts have focused on the aerodynamic design as air resistance is the most predominant factor that has to be overcome [2]. "
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    ABSTRACT: The current International Human Powered Vehicle Association world records for faired bicycles stand at 133.284 km/h for the 200m flying start speed record and 91.562 km for the hour record. Traditionally the recumbent bicycles that have been developed for breaking one of either of these records have been optimized around a specific, relatively small rider, enabling the overall size to be kept small. Creating the smallest frontal area possible and optimal aerodynamic shape were then the design goals. This paper discusses the development of the Velox recumbent bicycle, which has been designed using another approach. The power required to break either of the records depends mostly on air resistance. Therefore small riders have the advantage of allowing for smaller frontal areas, whilst larger riders are able to provide more power. Performance optimization, lead to a design based around an average 1.95m tall male rider for Velox. The aerodynamic shape of Velox was then developed around the above criterion and designed with CFD and validated with wind tunnel and road tests. Essential for the rider's performance is that the rider feels comfortable whilst riding the bicycle. Therefore the uncontrolled lateral dynamics and the required rider steer control input were investigated. The bicycle's geometry was optimized for low speed stability and the required control input.
    Procedia Engineering 12/2012; 34:313–318. DOI:10.1016/j.proeng.2012.04.054
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    • "Therefore, OCw could increase substantially after 3,000 m due to the combined effects of environmental conditions and fatigue. In addition, _ VO 2max decreases in relation to altitude, dropping to approximately 70% of the sea level _ VO 2max at 5,000 m (Bassett et al. 1999; Péronnet et al. 1989; Mazzeo 2008). An increase in OCw may also decrease _ VO 2 reserve, causing a higher fractional use of _ VO 2max , especially in the final ascent phase. "
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    ABSTRACT: The purpose of this study was to test the hypothesis that mountaineering experience decreases the net oxygen cost of uphill walking (OCw) on steep mountain trails and in ice and snow conditions. OCw was measured during an ascent of Mont Blanc in eight experienced alpinists and eight non-alpinists who were matched for sex (4 + 4) and low-altitude aerobic power (V(O)(2)(max) 50-55 ml kg(-1) min(-1)). Subjects carried a breath-by-breath gas exchange analyzer and a GPS. V(O)(2)(max) at altitude was estimated from measured low-altitude V(O)(2)(max) using Bassett's equation to calculate fractional use of V(O)(2)(max) during the ascent (FV(O)(2)(max)). OCw was calculated as the difference between V(O)(2) while climbing minus resting V(O)(2). At all elevations, Alpinists exhibited a lower OCw (P < 0.01). In all subjects, OCw increased when encountering ice and snow conditions. FV(O)(2)(max) remained stable around 75% at all elevations independent of experience or sex. In conclusion, the OCw is lower in experienced mountaineers compared to non-experienced subjects, and increases when going from steep rocky mountain terrain to ice and snow conditions, independent of mountaineering experience or sex.
    Arbeitsphysiologie 04/2010; 108(6):1209-16. DOI:10.1007/s00421-009-1334-9 · 2.19 Impact Factor
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    • "). Nonetheless, Bassett et al. (1999) estimate that cyclists' drag coefficient is typically constant when wind speed ranges between 50 and 60 km Á h 71 . Before the tests, the force balance was zeroed at a wind speed of 15 m Á s 71 , to exclude the aerodynamic drag of the power meter. "
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    ABSTRACT: The aims of this study were to measure the aerodynamic drag in professional cyclists, to obtain aerodynamic drag reference values in static and effort positions, to improve the cyclists' aerodynamic drag by modifying their position and cycle equipment, and to evaluate the advantages and disadvantages of these modifications. The study was performed in a wind tunnel with five professional cyclists. Four positions were assessed with a time-trial bike and one position with a standard racing bike. In all positions, aerodynamic drag and kinematic variables were recorded. The drag area for the time-trial bike was 31% higher in the effort than static position, and lower than for the standard racing bike. Changes in the cyclists' position decreased the aerodynamic drag by 14%. The aero-helmet was not favourable for all cyclists. The reliability of aerodynamic drag measures in the wind tunnel was high (r > 0.96, coefficient of variation < 2%). In conclusion, we measured and improved the aerodynamic drag in professional cyclists. Our results were better than those of other researchers who did not assess aerodynamic drag during effort at race pace and who employed different wheels. The efficiency of the aero-helmet, and the validity, reliability, and sensitivity of the wind tunnel and aerodynamic field testing were addressed.
    Journal of Sports Sciences 03/2008; 26(3):277-86. DOI:10.1080/02640410701501697 · 2.25 Impact Factor
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