Fluid Mechanics Webinars: Christophe Clanet talk video
Speaker: Christophe Clanet, LadHyX, CNRS, École Polytechnique, Palaiseau, France
Date/Time: Friday 1st May, 2020. 4:00pm BST/11am EDT
Title: The physics of road and track cycling
Image: Lucien Jonas, Petit-Breton, étude pour The final rush, 1905, Musée de la Piscine, Roubaix
Video: cambridge.org/fluidwebinar/clanet
Abstract: Even if the first bicycle was invented in Germany in 1817 by Karl von Drais, the Physics of cycling probably started in 1869 with the work of the Scottish mechanical engineer W.J.M. Rankine entitled "On the dynamical principles of the motion of velocipedes". Among the questions which have been addressed in the subject, stability is probably the most debated. First addressed in 1890 by J. Boussinesq ("Aperçu sur la théorie de la bicyclette") and F. Klein and A. Sommerfeld ("Stabilitat des Fahrrads") research continued with tens of contributions up to 2011 (see "Historical Review of Thoughts on Bicycle Self-Stability" by Meijaard, Papadopoulos, Ruina and Schwab). The questions discussed during this webinar seminar won't however be connected to stability but related to races:
For road cycling we will wonder why three jerseys? Tour de France, Giro d’Italia and the Vuelta in Spain are the three Grand Tours of professional road cycling. Three weeks long with daily stages, these three races all use three jerseys to distinguish the leader, the best sprinter and the best climber. We will first discuss the physics of road cycling and show that these three jerseys are respectively associated with three different dynamical regimes. We will then propose a phase diagram for road cycling which enables the discussion of the different physiological characteristics observed in the peloton.
For track cycling we will wonder why Team Great Britain is so strong? Analysing the Individual pursuit of Graham Obree World Title in 1993 will be our starting point. We will then move to the qualifying 200m of Jason Kenny and finish with team pursuit. The main point will be to discuss why and how the fixed gear condition of track cycling changes the law of races.