The importance of aerodynamics for cyclists
Historically speaking, the terms cycling and aerodynamics go hand in hand. For these purposes, aerodynamics could be defined as the study of the forces that the air exerts on a rider who tries to pass through it on a bicycle.
As anybody who rides a bicycle is aware, the closer the body is to the bicycle frame, the less resistance the air exerts and therefore, the faster the bike will go even when the same amount of force is applied to the pedals. The same thing happens when you go downhill on your bike: even when you stop pedalling, logic tells you that the closer you hug the bike frame, the faster you will go.
When it comes to competitive cycling, the aerodynamic factor has come to be more crucial in time trials than in direct competition since the cyclist is not competing against other athletes and the wind becomes his or her direct rival.
In 1893 Henry Desgrance set the first men’s world one-hour cycling record in Paris with a distance of 35 kilometres. There have been numerous attempts to break the one-hour record since then but only 42 cyclists have actually been able to surpass their immediate predecessor’s distance until Victor Campenaerts set the current record of 55 kilometres in 2019.
Technological progress has contributed many improvements in the aerodynamics field. The invention of the wind tunnel was a turning point. Major bicycle manufacturers realized that if the wind tunnel was used to analyse the effects of air movement around solid objects, it could also be used to quantify improvements in bicycle design and materials to construct more efficient, faster bicycles. The teams soon began to include their leading cyclists in the aerodynamic analyses. Thus, once the data on materials had been analysed, they also quantified the aerodynamic values of the cyclist in different positions.
Technological progress: the key factor for proper application of aerodynamics to improve performance
I personally had the immense good fortune to form part of an analysis group. It was an enriching experience that gave me a deeper understanding of the importance of the rider’s posture on the bike. It should be noted that the rider accounts for roughly 80% of the resistance volume and the remaining 20% corresponds to the material: frame, wheels, etc.
Evidently, the faster the cyclist is going, the more aerodynamic resistance he or she will encounter. As a general rule, at speeds below 20 km/h the wind resistance is negligible. Between 20 km/h and 35 km/h it has a certain relevance and from 35 km/h on the importance of aerodynamics increases exponentially.
In recent years we have seen how the Union Cycliste Internationale (UCI) has banned certain positions in the interests of safety and to the detriment of the riders’ aerodynamics, thus preventing more dramatic improvements in the performance of cyclists of different eras: the 650-mm front wheel, Spinacci handlebars, Graeme Obree‘s “egg” posture, Chris Boardman‘s “superman” position, the forearms resting on top of the handlebars, adopting the “egg” position during descents, etc.
Studies have even been published on the difference in aerodynamic resistance of the same cyclist gripping the handlebar at the lowest part (drop handlebars) and from above (on the brake hoods) with a 90-degree bend in the elbows. Interestingly, and contrary to the traditional manner, the rider adopts a better aerodynamic position when holding onto the upper part of the handlebar, thus achieving a more compact posture.
That is why today you will only see experienced cyclists holding the drop (the curved part) to sprint or when descending, since this position enables the strongest grip on the handlebar and therefore gives them the best control.