Il n'y a pas de côte trop difficile, il n'y a que des braquets inadaptés. C'est ce que démontre le cycliste vedette de cette vidéo qui monte du 32% avec un braquet équivalent à ENVIRON 11:120 dans son 1er essai et 11:104 dans le second. Non, il n'a pas un plateau de 11 à l'avant et 120 dents à l'arrière, mais une démultiplication intermédiaire.
A part ça, Franck a manifestement lu Confucius, Lao Tseu ne faisait pas de vélo Malgré tout, au-dessus de 40% je doute qu'à moins d'avoir un vélo trèèèèèèèèèèèèèèès long on arrive à trouver un braquet adapté. Je m'aperçois que la vidéo est accompagnée d'une explication technique : Cycling Instructor/Aerospace Engineer, Dan Gutierrez uses a special bike he created to climb straight up Fargo Street; the toughest hill in North America with a 32% grade for over 1/10 mile in length. This video was shot on the day of the LA Wheelmen Fargo St. Hill Climb on March 16th, 2008. Brian DeSousa did the tripod and hand-held video camera work, and Dan shot the helmet camera video. This video demonstrates that the concept of adding a second crank to a single bike and modifying the rider position, allows stable operation with ultra-low gears at very low speeds on a very steep hill, but at a much lower bicycle weight to lug up the hill compared to using a tandem bicycle with similar gearing. Since many have asked, the gearing used was as follows: Left side drive 20T lower crank, 45T upper crank. Right side drive 20T (same shaft as the 45T on the left), rear cassette 11-32 8sp The two gears used in the video were on the 32T and then 28T cogs, 7.5 and 8.6 gear inches respectively.