Wind Tunnel Testing

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Under the meticulous eye of the legendary aerodynamic guru, John Cobb, I underwent testing in the Texas A&M Wind Tunnel with the hopes of discovering my ideal race day set up. TriShop invited several athletes down for the trip, and I owe the TriShop team a huge thanks. “Free Speed” is never really free…It was a massive undertaking – the mechanics were constantly assessing options, the guys were relentlessly analyzing data, and Travis was video-ing and snapping pictures all day long. And even after the knowledge we gained around “Free Speed,” John was quick to remind us that it’s still all about the engine. This was just one piece of the puzzle.

TriShop is constantly raising the bar; I’m so glad they invested in this experience. We literally used every minute they gave us to test out various options that a consumer may have. From helmets to wheel choice, from aero-positioning to bottle placement, from bike frame selection to apparel – we covered an immense amount of options. This makes TriShop more knowledgeable when it comes to bike fits and bike purchases – they have the numbers to back up their insights. It was fascinating information and truly very valuable.

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The back half of the day, each athlete had the opportunity to test out several options that were specific to our race-day selections. My questions centered around wheel selection, apparel choices, helmet options, and some positioning/accessory placement on the bike. My fit is very aero, as is the bike frame itself, and the aggressive fit works for me – I can get off the bike after a hard 56 miles and feel fresh enough to run another swift 13.1. But with the smoke testing we could visualize a few minor areas of improvement. First, my watch (Garmin 920). This added unnecessary drag. With the Zipp Vuka Carbon BTA (between the arms) bottle cage and Vuka Alumina BTA mount (super slick and lightweight!) I can utilize the bike computer, the Garmin Edge, that snaps right on there and don’t have a need for the Garmin 920 watch. Horizontal BTA hydration systems are aerodynamically faster. And with an option for an integrated computer, my watch problem is solved. I don’t need it on the swim – I can catch the time as I exit – don’t need it on the bike since I have the Garmin Edge. Then in T2, I can grab my racebelt and visor and Garmin 920 in one quick sweep as I run out. The Garmin 920 will be loosely snapped in place so all I need to do is tighten it once I slip it on…easy. What this means for another athlete though – just flip your watch around so the watch face is directed inwards. Less drag that way. And you can actually see the watch better as it’s pointed towards you rather than away.

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As for wheels, on my bike the Zipp wheels tested by far the best. They were so superior it wasn’t even funny. My Felt IA FRD hides the back wheel well so the front wheel didn’t matter as much with a straight headwind. When the cross-winds interrupt the Felt IA FRD ride though, the front wheel matters. Deeper is better. At the end of the testing all the combinations we could come up with, we found that the 808/Disc is the best set up for me. I can run the 404 front/Disc rear too, depending on wind condition, and the aerodynamic benefit won’t be affected very much either. As long as they are Zipp wheels. The tires I tested best in were Zipp as well. Done deal.

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Bottle placement is going to typically be best as between the arms horizontally and a rear bottle, nothing inside the frame. Between all the athletes, on different bikes, the best bottle placement inside the frame differed, so that’s going to be an individualized matter of selection. More consistently we saw that the down tube presented the better option over the seat tube, but again, that varies somewhat from one bike to the next, from one rider to the next.

I tested a one piece Hincapie Sportswear kit verses the two piece kit. Hincapie provides custom apparel and it’s very high quality – Click here to see the skin suit I’ll be wearing this year. Both the one and two piece options both exposed the same amount of skin (and skin is slow), and both tested equally aero. That means that I choose to race in whichever is most comfortable (or cute!)…For other brands or options, you could look for a suit with half sleeves to cover more skin, and sometimes a one piece may have an advantage over a two piece – I’ve seen it before. But this is not the case for Hincapie. They’ve covered their bases.

On to the lids. These are pretty individualized from what we saw. It depends on your riding style and how rounded or flat your back is when riding. For me, the Rudy Project Wing57 tested the best, and even hid my ponytail braid. It tests fastest without the shield and without the center vent cover, which was surprising, but it was actually designed to be left open for better ventilation – so I won’t complain!

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I’m grateful to have an aero advantage after Cobb’s watchful eye. I’m confident in my gear, component, accessory, and positioning choices and now that I’ve made those aero upgrades, I’m ready to continue to fine-tune the engine.

Training | | 1 Comment

One Response to Wind Tunnel Testing

  1. Mike says:

    Thanks for the write up about the wind tunnel. I’m surprised the watch has an effect. Do you mind telling me how many watts you found the watch to drag? Thanks

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