They also discovered this:
https://www.youtube.com/watch?v=DZnrE17Jg3I
According to their tests on six athletes (cyclists and triathletes), the average time saving was about a minute over a 40K time trial, just from shaving one’s legs. The amount of time saved depends a great deal on where that person stands on the Chewbacca scale. (Yes, it’s exactly what you think it is, a “hairiness” scale.)
It started off with pro triathlete Jesse Thomas heading to the Specialized Win Tunnel (no “d”) for a day of testing various components, gear, outfits and body positioning, to discover the most aerodynamic choices. The disc cover had a similar aerodynamic profile as a disc wheel. The smaller aero helmet was better than the long aero helmet in crosswinds. A sleeved suit was faster than a sleeveless suit. Then Thomas said he had to get pictures for sponsors, but forgot to shave his legs that morning. He would have to shave his legs (which rank very high on the Chewbacca scale, 9 out of 10) anyway, so why not test the difference between hairy legs and shaved legs in the wind tunnel. He said this partly as a joke and partly for fun, because people have often wondered if there is any real aerodynamic benefit to shaving one’s legs for a bike race. Many joke about it and make up outrageous and unbelievable claims, just to get some laughs. This time, they would study it scientifically.
[from Jesse Thomas’s recent article at the Triathlete/Competitor website]
http://triathlon.competitor.com/2014/07/photos/secrets-wind-tunnel_102363#iL0iZErPzecXHZxw.99
All the previous tests were performed in 60-second chunks: The wind would start, then a countdown, then 60 seconds of data holding your position, then the wind stops and youâre done. Every once in a while Mark and Chris would run two or three 60-second tests in a row, just to make sure the data was consistent.
So I got on the bike, the wind fired up, the countdown began and 60 seconds went by. But instead of the wind stopping, it kept going. Then another countdown, and another 60-second test. Then another, and another, and another, and another. Six 60-second tests went by; I wondered what the hell Mark was doing. Is he playing a trick on me? Iâm starting to get tired, and itâs cold in the wind tunnel in January!
Finally the wind stops; I hop off the bike and enter the control room. The mood is kind of creepy, the exact opposite of our â80s party just a few minutes ago. Everyone is silent and I see Mark staring blankly at the computer screen. Eventually, I say âHa, that was fun. What did we discover? One watt? Two watts?â
Mark doesnât even look at me. He just stares into the screen and says, âNo. Itâs impossible. It canât be.â I feel like Marty McFly in âBack to the Futureâ witnessing Dr. Emmett Brownâs â1.21 gigawattsâ tirade. Eventually I say, âMark, whatâs the deal? Did it do anything? Youâre kind of creeping me out, dude.â
Finally he looks up from his computer screen and says with absolute conviction, â15 watts.â
I just start laughing, âThatâs funny. Haha. Yep. Iâm a hairy dude. I get it. But seriously, what happened?â
âSeriously. It was 15 watts faster. I canât explain it. I canât believe it. Thatâs why I ran so many samples. But thatâs what itâs sayingâ15 watts for your shaved legs.â
In the case that this test was some kind of miscalculation or my legs are just freakishly hairy, we waited to tell the story until Mark and Chris had some time to corroborate the data. As it turns out, Mark has now tested five other individuals and seen drag savings of anywhere from 7 to 13 watts depending on where they rank on the 10-point âChewbacca Scaleâ he created (seriously). Since the other riders scored only 5 to 8 on the Chew-scale (I was the only 9), a slightly lower drag reduction was expected. Yes, my legs are freakishly hairy, but the calculations were correct.
So there you have itâthe secrets of my day at the wind tunnel. I saved 2â3 watts on my helmet and wheels, 5 watts with my arm position, 8 watts with my new kit. But the big winner was the 15 watts I saved by clear-cutting the forest off my lower legs.
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