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TdF and recumbents
Pat ? wrote:
How would a recumbent handle the Tour? Anyone that claims to provide a definitive answer is blowing smoke up your backside, since the information does not exist to provide the answer. You will find a lot a negative answers based on misinformation by "experts" who have no experience or knowledge, however. As a starting point, consider that there are only a few hundred state of the art performance recumbent bicycles in existence (compared to tens of thousands (or more) of state of the art upright bicycles), and most people have never seen one unless they attend a recumbent oriented racing series (and even there, most of the recumbents will not fit that definition). Furthermore, of this relative handful of recumbents that are lightweight (less than 8 kgf) and put the rider in an aerodynamic position, only a small fraction are ridden by riders who could keep up in a CAT 2 race on an upright, to say nothing of UCI professional level riders. So all observations made of recumbents in the real world can pretty much be thrown out as irrelevant to the original question. Unless someone can demonstrate that upright riders can develop significantly more sustained power than recumbent riders [1], there can be little doubt that a recumbent with a seat-back 20° to 30° from the horizontal and the pedals 20 to 25 cm higher than the seat will be faster on the flats than a drop bar road bike or an upright TT bike. This advantage becomes more significant in windy conditions, due to lower wind speed within the 1 meter boundary layer between the atmosphere and the ground. For equally talented and trained riders, the recumbent lowracer would be faster during a flat to rolling time trial or on a breakaway on a flat stage. An upright sprinter can develop significantly more short term power than a recumbent rider, based on the available information. However, as anyone who has watched a race knows, sprinting prowess is of little advantage, unless the sprinters are in the leading peloton near the finish of the stage. Due to the lower frontal area of a recumbent lowracer and the inability for an upright to effectively draft the recumbent, the upright sprinters would not be in a position to use their advantage in short-term power. And of course, there are the mountain stages, where conventional wisdom says that recumbents can not climb. The first thing is to throw out all personal observations here, since they invariably involve recumbents that are heavier than a state of the art CFRP lowracer and riders considerably less able than a UCI professional. The key is to remember that aerodynamic resistance increases with the square of the rider's airspeed. Therefore, for average club riders, both upright and recumbent riders will be going slowly enough that rolling resistance and mechanical losses in the drive train will dominate, which favors the upright. However, with a professional level rider putting out 400W on a climb, speeds become high enough that aerodynamics does matter, even on a relatively steep climb, and an upright rider out of the saddle is not very aerodynamic. Is the aerodynamic advantage of the recumbent at very high rider output levels enough to compensate for the advantages of the upright? I do not know, and more importantly, neither does anyone else. [1] The few studies down indicate that this is NOT the case. -- Tom Sherman - Holstein-Friesland Bovinia "People who had no mercy will find none." - Anon. |
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