The impact of drivetrain configuration on overall cycling efficiency: simulations, experiments and case studies from World Tour time trialing

Authors

  • Bart Blockmans Classified Cyling, Damplein 23, 2060 Antwerp, Belgium
  • Sander Laseur
  • Hugo de Jong
  • Viktor Verschaeve
  • Bruno De Naeyer
  • Roëll van Druten

Keywords:

drivetrain efficiency, metabolic efficiency, model-based optimization, experimental validation, time trialing

Abstract

Despite frequent displays of undisputed dominance in cycling’s biggest road races, time trialing remains a test of precision, where victory is often determined by razor-thin margins. In all of the major time trials of the 2024 season, champions were separated from runners-up by time differences of less than 0.5% (or 9 seconds per 30 minutes). As a consequence, the pursuit of cycling efficiency has never been as relentless as today, with countless hours of wind tunnel testing being used to scrape off the last fraction of a watt from a cyclist’s jersey. Besides aerodynamic efficiency, bicycle drive-train efficiency has received increased interest in recent years. On the verge of what could be a paradigm shift in bicycle drivetrain technology, the traditional front derailleur-based 2x systems are increasingly being challenged by “derailleur-killing” technologies such as 1x configurations and drivetrains equipped with hub gears. Whether or not said technology shift will actually happen, and if so in which of cycling’s many disciplines, depends to a large extend on the proven efficiency of these new drivetrain concepts. In the current work, a comparative analysis of various drivetrain configurations is presented, based on a combined simulation-based and experimental approach, with case studies from World Tour time trialing in the 2024 and 2025 seasons.

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References

Wilson, D. G., & Schmidt, T. (2020). Bicycling science. MIT press.

Spicer, J. B. et al. (2001). Effects of frictional loss on bicycle chain drive efficiency. J. Mech. Des., 123(4), 598-605.

Blockmans, B. et al. (2023). Numerical and experimental investigation of the efficiency of Classified Cycling’s powershift hub. Classified Cyling white paper.

SKF (2014). The SKF model for calculating the frictional moment. SKF

Published

2025-11-19

How to Cite

Blockmans, B., Laseur, S., de Jong, H., Verschaeve, V., De Naeyer, B., & van Druten, R. (2025). The impact of drivetrain configuration on overall cycling efficiency: simulations, experiments and case studies from World Tour time trialing. Journal of Science and Cycling, 14(2), 1. Retrieved from https://www.jsc-journal.com/index.php/JSC/article/view/1010

Issue

Vol. 14 No. 2 (2025): Special Issue of the 2025 Science & Cycling Congress | Lille - June

Section

Science & Cycling Conference, Lille 2025

Copyright (c) 2025 Journal of Science and Cycling

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