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The four main cycling positions (a) the traditional position, hands on brake hoods (b) the dropped position, hands on drops, arms bent (c) the hill descent position (d) the time trial position.

The four main cycling positions (a) the traditional position, hands on brake hoods (b) the dropped position, hands on drops, arms bent (c) the hill descent position (d) the time trial position.

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In elite cycling the resistive force is dominated by aerodynamics. Be it on the roads or in the velodrome, the sport has many examples where aerodynamics has won and lost races. Since the invention of the bicycle, engineers have strived to improve performance, often by reducing aerodynamic drag. Over the last 50 years a number of authors have prese...

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... (the traditional time-trial position of the time). Aerodynamic drag was reduced even further, by 28% from the reference upright position, when the rider was in the hill-descent position (with hands in the centre of the handlebars, out of the saddle, straight legs and chin close to the handlebars). The four main cycling positions are shown in Fig. 1. Kyle (1991b) reported on wind tunnel investigations carried out at California Institute of Technology in 1986. At this time tri-bars were not commercially available. Tri-bars allow the rider to rest their forearms on supports near the handlebar, creating a lower position with a greatly reduced frontal area ( Fig. 1(d)). Kyle (1991b) ...
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... cycling positions are shown in Fig. 1. Kyle (1991b) reported on wind tunnel investigations carried out at California Institute of Technology in 1986. At this time tri-bars were not commercially available. Tri-bars allow the rider to rest their forearms on supports near the handlebar, creating a lower position with a greatly reduced frontal area ( Fig. 1(d)). Kyle (1991b) investigated another position, which involved having the rider place their arms behind the seat, akin to a speed skating position. An aerodynamic chest support and modified steering behind the seat allowed this position. This position reduced the drag by 12%. Since the introduction of tri-bars development of this ...
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... that for conventional bikes the drag rises as the yaw angle increases up to approximately 10°, and then gradually decreases again. This was not the case for the LotusSport monocoque bike: as the yaw angle increased from zero the drag did not rise; in fact it steadily decreased, and at all angles remained less than the drag on the traditional bike (Fig. 10). This interesting result was due to the aero- dynamic sail effect created by the slender blade of the monocoque frame. The effect of a velodrome crosswind was investigated using a computational iterative process. The results showed that the tradi- tional bike, as expected, loses a lot of time when subject to a cross wind. However, due ...
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... aerodynamics of mountain biking have been investigated far less than in track or road racing. The reasons for this are apparent when considering the additional losses and far lower average speeds in this discipline. Sunter & Sayers (2002) investigated the advantages of attaching a fairing to the front wheel of a downhill mountain bike (Fig. 11). With a 10 mm displacement between wheel and deflector the drag reduction was 10%. This reduction in drag was found to decrease as the deflector moves away from the wheel. At a speed of 15.5 m s -1 the drag force reduction of using the deflector was 0.78 N. The total aerodynamic force on a mountain bike was quoted as 36 N, giving a ...

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... The F air is related to the coefficient of aerodynamic drag (C d A) and of the wind. 6,7 The F roll , which represents the contact forces between the ground and the tyres of the wheels, is affected by the road surface, 8 the vertical force applied to the tyres and the tyre inflation pressure. 9 The F friction corresponds to the frictional losses at the bearing and transmission chain and is generally considered negligible. ...
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... Drafting behind another cyclist can significantly reduce air resistance (Blocken et al., 2013), but it is not allowed in IM triathlons. However, if external assistance is used for the sub7 project, a group of cyclists could ride in front of the « racing » triathlete which would allow him to ride at a significantly higher speed and reduce energy expenditure, oxygen consumption (Lukes et al., 2005), heart rate, lactate concentration and perceived exertion (Hausswirth et al., 2001). Furthermore, this would allow the « racing » triathlete to run faster after cycling since he would have expended less energy while cycling. ...
... The magnitude of the effect of drafting may depend on many factors, such as the number of cyclists in the group, the position of the cyclists, the distance between each cyclist as well as the drag area of the lead cyclists (Lukes et al., 2005). A cyclist drafting as closely as possible behind a lead cyclist may experience a drag reduction of as much as 15-50%, which may reduce to 10-30% at a distance of one bicycle (Crouch et al., 2017b). ...
... Various studies have investigated the aerodynamic drag of the time trial position using the wind-tunnel tests (García-López et al., 2008;Grappe et al., 1997;Jobson et al., 2008). Further, few studies exist for the effect of aero handlebars, which may be essential adjustments when fitting a bicycle (Kyle, 1989;Lukes et al., 2005;Oggiano et al., 2008Underwood & Jermy, 2013. García-López et al. (2008) reported a significant reduction in aerodynamic drag of about 14% when the height of the aero handlebars was lowered during riding in a TTP. ...
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... Through extensive wind-tunnel testing the scientific literature has developed a comprehensive understanding of the role of air resistance in cycling and the potential performance benefits obtained from positional changes during competitive cycling events (e.g., Blocken et al., 2018;Lukes et al., 2005;Underwood & Jermy, 2013). On the other hand, the biomechanical and physiological consequences of such aerodynamic positions (AP), which have shown negative effects on power producing capacity (Ashe et al., 2003;Fintelman et al., 2015a) and metabolic efficiency (Fintelman et al., 2015b;Gnehm et al., 1997;Peveler et al., 2005), are not fully understood. ...
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