Just lowered my cda by .02

[coachboyd]

So, when I was down in Florida I did a little bit of time trial testing. The biggest hill was a bridge so I might as well. I had always subscribed to the theory that lower is better when time trialing and would always try to get my bars as low as I could. So, with training wheels, jersey, shorts, regular helmet, and a bottle in the frame I got a cda of .246. It was pretty decent and that number would go down with race gear on. I crunched some numbers at an online calculator I like to use
http://bikecalculator.com/veloMetricNum.html
(.246 cda, .004 crr, 340 watts, 69kg body weight, 9kg bike weight, no wind, no gradient, 300m above sea level)

And the results matched up very well with a time trial that we do once a month on Lowes Motor Speedway in Charlotte. It's a ten mile time trial, very fast road conditions, and I would always seem to be just over 20 minutes. When I plugged in the numbers I came back with a time of 20:30. Pretty much spot on without having race gear on.

So, today I tried something. I flipped over my stem (so I was a bit more upright). I angled the bars upward and adjusted the pads so my elbows were almost touching. The aerobars are set about 3 inches apart (very narrow). I had tried the position with the bars angled upward before, but my stem was always lower and I could never produce any power (often struggling to push 35 watts less than I could do on the road bike). So I had gone back to the aerobars parallel to the ground. . . until today.

I rode in this position before testing out the numbers just to see if it was comfortable. . .and it felt faaaaast. I hurried home, got the iBike setup and went to go see what my cda numbers were.

When I came back and downloaded the info it came back as a .223!! I found a position where I felt like I could deliver all the power from my road bike, and I was even more aero than before. It is very similar to the video being shown about Tom Danielson's new time trial position. Arms very close together, bar higher than before, arms raised up a bit.
http://velonews.tv/?articleID=2589

Going back to the online calculator and plugging in the new numbers for the ten mile time trial, I will get a time of 19:50 with the same wattage. This means without having to gain any watts or spend any money on wheels or helmets I just saved 40 seconds over the course of ten miles! That's almost two minutes faster over a 40K time trial.

Without having the numbers in front of me I may have just dismissed this position. The bars were up higher so that MUST be unaero, right? Well, because of the iAero I was able to test this out and find a position that was comfortable and a lot quicker.

I will try to get some video over the next couple days of me in this new time trial position compared to the old one. Within the past few months there have been some radical changes to the "standard" time trial position and they are finding what works for some people doesn't work for others. To find your own personal fastest position you either have to pay 600 dollars an hour for a wind tunnel, or you can have a power meter that will give you that info whenever you want it for about the same cost as that hour.

[coachboyd]

Looks like somebody else may have seen this post
http://www.youtube.com/watch?v=KhKHSjL7pjQ&eur

Check out about 25 seconds in