Aero watts. Aero whats?

When I first heard that Gear Grinder was working with Blue Cycles and new Blue Triad purchases came with wind tunnel time I got really excited. We are always looking for ways to go faster on the bike and improved aerodynamics equate to free speed so I jumped at the chance to get in the tunnel to see what improvements could be made. So thanks to Blue Cycles and Chance Regina for making this happen.

The A2 wind tunnel, located just outside of Charlotte, NC in Moorseville, is one of the leading wind tunnels for cyclists and triathletes in the country and my experience there made me understand why. The staff has hundreds of hours of experience working with cyclists and triathletes and that knowledge goes a long way when the subtlest changes can improve your wind cheating abilities or make riding downright uncomfortable.

My day started with a 3:00 AM wake up call and short drive to the Milwaukee airport for a 6:10 flight and connecting flight in Atlanta. I got to Charlotte ahead of schedule and made my way through baggage claim and grabbed my bike. It was going flawlessly, or at least I thought it was until I got to Budget, where I made my rental reservation, and there were no cars. I was actually 5th in line at that point and decided to cancel and try to get a car from someone else. Nope. No cars available at the entire airport. (However, at the Thrifty car rental office I ran into Dick Beardsley. I didn't know who he was at the time but he told me he was speaking at the ZAP Fitness camp in Blowing Rock, NC and I later looked him up. We struck up a short conversation and I was on my way. Had I known who he was I would have asked him for a ride.) It was now 12:15 and I had a 1:00 appointment to get to 45 minutes away. My only option seemed to be a taxi. I knew it would be expensive, and it was, but I had no other option if I wanted to keep my appointment. Ninety-five dollars later I was at the A2 wind tunnel and only 15 minutes past the hour. After putting my bike together and doing a short warm up we jumped right into the testing process.

The wind tunnel is a long corridor with giant airplane turbines at one end and intake vents at the other. In the middle was a Computrainer hidden within a round platform with four braces sprouting from the top. The platform rotated to simulate varying degrees of crosswind. Cameras are housed in each of the side walls and ceiling to capture video for later review.

A computer image is projected in front of the rider displaying all the pertinent information like speed, watts, aero watts (which is the amount of power it would take a given rider to pedal at a given speed, in my case it was 30 mph, which is pretty standard,) elapsed time and a few others. The output the rider is most concerned with is watts and aero watts. Each wind tunnel session is a series of short tests. The first few of the tests is to establish a baseline and get the rider antiquated with the process. Then each subsequent test is of a small change in equipment or position and each time you hope to see a lower reading of aero watts. Before each test a 'tare' sample is taken where you sit on your bike in the aero position absolutely still. Then the fans start up and the rider begins pedaling up to and maintains the predetermined wattage, usually just under threshold watts.

For my tests the first change was head position and this ultimately yielded the largest improvement in aero watts at 28. The other changes we played with were aerobar angle, aerobar height, aero pad width, which all told only gave me another 7 aero watts. The last run we did was with a different aero helmet that looked to be a better fit for my position and it was. All told I managed to save myself just under 10% at 30 mph, which anyone will tell you is huge.

When the testing session was over Mike Giraud, the bicycle specialist at A2, made me a DVD of the entire session including a spreadsheet with detailed information on the individual runs as well as 3-point video for each. I haven't had a chance to look over the DVD yet but am eager to see the videos of the different runs and see if there is an obvious visual difference in the positions I was in. From my perspective the new position felt different but not radically so.

At the end of the day the lesson learned was head position and helmet choice can potentially make the biggest difference overnight. Time can be spent to continuously lower the front end of your bike so the shoulders are parallel to your hips like the fastest ProTour riders you see, but for someone focusing on IM distance races that just isn't realistic. Don't forget the riders in the Tour don't have to run a marathon when their finished riding.

Although it was a long day (I didn't get home until after 1AM) and can be quite costly with bike expenses and cab fare I enjoyed my experience greatly. I would recommend it to anyone who is willing to spend the time and money to gain some headway in the largest battle we face when riding our bikes- the wind.

Also- Mike G. was kind enough to give me a ride back to the airport so I didn't have to shell out another Benjamin. So, thanks Mike!