The Influence of the Inter-Relationship of Leg Position and Riding Posture on Cycling Aerodynamics

Abstract

Aerodynamics is an important factor affecting cyclist performance, as at the elite level 90% of rider energy is used to overcome aerodynamic drag. As such, much effort has been channeled into understanding the detailed flow around cyclists, since small gains can produce large rewards. Previous studies have shown that cycling aerodynamic drag is sensitive to leg position during the pedaling cycle; however, a systematic analysis comparing the impact of leg position between different riding postures is yet to be undertaken. To address this question, we compare the impact of leg position for two elite-level riding postures: the standard sprint and pursuit body positions. The comparison shows that the effect of leg position on drag is not consistent between the two riding postures, as the altered flow associated with different leg positions is influenced by the wakes from and proximity of other upstream or nearby components, such as the arms. This study reveals the inter-relationship between leg position and riding posture; and suggests that the flow associated with varied leg position should include surrounding geometrical components to obtain and understand the full aerodynamic impact. Practically, the results are valuable for optimizing the posture and improving skin-suit design for drag minimization.

The influence of crosswinds and leg positions on cycling aerodynamics

“…The ever-increasing significance of understanding cycling aerodynamics is represented by the expansion of work produced within the last ten years (Crouch et al 2017;Blocken 2020, 2021). Multiple engineering approaches have been formulated among teams to reduce the aerodynamic drag, which include: adjusting the position of the cyclist (Defraeye et al 2010;Giljarhus et al 2020;Polanco et al 2020;Wang et al 2022;Schaffarczyk et al 2022;Giljarhus et al 2023), optimizing the geometry of the cycling equipment (Chabroux et al 2012;Castellini et al 2020), improving the skinsuit design (Underwood and Jermy 2011; Oggiano et al 2013;Zheng et al 2021), and taking specific strategies in drafting or overtaking (Barry et al 2014;Blocken et al 2018;Spoelstra et al 2021;Cantos et al 2023). The above researches emphasize the importance of understanding fundamental flow physics in enhancing the aerodynamic performance of cyclists.…”