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aero helmets
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by DomT126 on November 1, 2007
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approximatley how much time can be saved with a aero helmet in a 40k race over a standard helmet?
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RE: aero helmets
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by jimmieb on December 15, 2007
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According to the Pro Bike Kit brochure it can help beat the wind by a hundredth of a second. However the small amount of time you gain will proably be wasted by the extra time it takes to get on.
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RE: aero helmets
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by drghs3 on January 25, 2008
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JimmieB real funny. Don't quit that day job . . .
To the question. The studies I have seen tend to say from 30-45 seconds. What is interesting, is the disagreement on the position of the head-helmet that saves the most time. The recent article on the subject in triathlon said the back tip should be down and the face looking forward. But aero- guru John Cobb claims that his wind tunnel testing with Lance Armstrong suggests otherwise. "In Lance's case I was able to show that his drag dropped a bunch when his face was down and the helmet tail was sticking pretty much straight up. I had to run several tests to convince everyone this was the case. The numbers don't lie, and I was sure we had found some speed." See article at http://www.slowtwitch.com/mainheadings/techctr/helmets.html So the jury is out on that one.
To me the issue isn't whether to wear an aero-helmet or not, but for most triathletes the issue is not to waste the time saved from the helmet with other not so aero-practices. I am amazed how many triathletes will wear an aero-helmet (and frame and wheels to match) and then piss away those advantages with the following time wasting practices (all for a 40k) -
1. Bottles behind the seat. The research suggests that this acts as a brake. Costs about 35-40 seconds. Other crap behind the seat - tubes, food, etc. - adds to that.
2 Bottle on the seat tube. Costs about 10 seconds.
3. Aero-seat post. Costs about 25 seconds.
4. Not using a Profile type bottle in front on the aero-bars. Such a bottle saves about 30 seconds.
5. Not having a bottle on down tube. A down tube bottle saves 30 seconds.
All of the above from http://www.slowtwitch.com/mainheadings/techctr/waterbottles.html
What else saves time? Body position (stay aero-, ride knock-kneed with knees close to the seat tube), keep jersey zipped, and shoe covers.
Another time saving tip, made awhile back by Peter Reid. It doesn't make sense to be a weight weenie or an aero- weenie and then lug around 2 or 3 or 4 bottles of water on your bike.
Most standard cycling water bottles are 24 ounces or about 7/10 of a liter. If you have two of those on your frame, that is about 3.3 pounds of water you are lugging around. If you add two MORE bottles to your behind the seat bottle holder, you are carrying 6.6 pounds of water total. Add a 32 ounce Profile bottle on the front, and you are carrying about 8 pounds of water.
So it doesn't make much sense to get an expensive aero-helmet and then piss away the time saved with a behind-the-seat-bottle carrier, seat tube bottle carrier, bad position, and luggin 3-8 pounds of water.
Dr. G
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RE: aero helmets
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by heysax on February 1, 2008
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Based on my experience last yr, over about an hour of effort, the helmet can save 1-1.5 minutes, & I am told the most cost-effective way of shaving time. All of the other advice Dr. G gave is key as well. Aero-postion/efficiency can also shave the same amount of time as a helmet, plus a disk wheel. On a 19 mi course I regularly do last yr, just by adding a disk wheel & dropping my stem 1 cm to make me more aero, my time dropped by 3 minutes!
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