Looking back at my trip to A2

Nearly 4 years ago (has it really been that long... geez) I loaded up my humble little Planet X Stealth and trekked over to North Carolina to get fast at A2 Wind Tunnel. Being that it's one of my most popular posts, I thought it was about time to have a look back (you know, to pad my post count) and give you my current thoughts about the time I got to spend there. Here's the link to the original thread.

First, let me preface by saying I thought I had done my research before ever laying down my credit card number. I had read as much (although, especially at the time, finding information from guys who had been, and would share anything of it with some guy asking for handouts was not very much) as I could trying to use my time as smartly as I could. I even enlisted John Cobb's (who was kind enough to take the time to help set me in the right direction.) input on what to do and what not to do. I even saved that email and think I can share it.

I would suggest not testing with the rear disc because air breaks off of them at different yaw points, they are not consistent, and it makes it hard to pin point real improvements. Wear what you are going to race in and maybe test one other outfit. Bare skin is always slower than covered skin. test helmets, turtling is OK for TT races but I find it distracting for triathlons. Test several helmets and pay attention to the "feel" of the ventilation compared to the drag. Test your water bottle placement, it is very individual.  Do a few repeat runs during the session, go back to a earlier configuration, just to be sure the tunnel data is consistent. If you have time it might be interesting to test your number location on your race belt, high vs low on your waist.  Elbow width vs comfort for swimming, 2cm can make a big difference. Have some fun, you will leave with a lot more questions as you think about it.  I do not use CdA numbers, I generally only look at drag. I do that because it is nearly impossible to figure surface area on a bike and pedaling rider in a yaw angle. If you test only at A2 then the drag will be consistent, CdA is used for different tunnel comparisons. I haven't found that you can assign a surface area number at "0" and then that be correct at a 15 degree yaw, so I look at drag and follow those trends.  There's tons of wheel data out on the net, don't waste your time testing wheels.  Position setup is a big deal so you can race with a lot of pelvic rotation, work on that but try to be realistic when testing and actually use the real position that you race with. Get somebody to snap a picture of you under power during a race and try to use that back shape, then work from there.  Have fun, learn lot's.

-John Cobb

At the time I thought I had taken his advice pretty well. Looking back, I skipped some of the most important parts, particularly the part about repeat runs. I admit, at the time I was so locked into the zone of "trying to fit it all in" that I didn't consider fitting more in was useless (or at the very least sketchy) if I didn't have repeatable results. I did re-test the final position I left with, which at least gives me a few less nightmares at night, but overall it was a sloppy use of time. John was 100% right, I left with a lot more questions as I have thought (for years) about it.

Was my time useful... absolutely. Was it optimal... not even close.
I did come out with a new, slightly more slippery position than what I arrived with, one I have used (and still use) since leaving the tunnel.

Tunnel time being used in the real world

Raising my hands was indeed a gain for me. Something many of the top fitters and aero testers pretty much universally recommend. However, from my own experiences I wonder if it is really as universally good for people who don't do their own testing as seems to be advertised. I'll share a small piece of my data from A2 to demonstrate what I mean.

Take with a grain of salt this is one man's opinion from n=1 data vs. guys who test a LOT of people, but if mine can be so particular about the exact angle of the tilt, how finicky is it for others? Also notice that at a certain point (30°, the highest I tested as it was the highest the bars would allow) going higher is not better, it's actually much worse. My data does correlate with the idea that raising hands some (from flat) is probably at least "not bad."


So... what's my opinion today, years later about going to the tunnel.

Honestly... it's save your money. You can use the Chung method (and/or Aerolab) to test to your hearts content and get good results. At least good enough to say "this helmet is better than that one." It's going to take a lot more time and work, but it is something you can do when you want without breaking the bank. The exception is if you are a die-hard numbers guy who really wants an A+ experience. I still look at my time fondly, it was a ton of fun. More fun than a week long vacation to the beach, (about the same cost...) ehh... but awesome and fun nonetheless. You are pretty well paying to save some (maybe a lot of) time and get easily repeatable (you know... if you repeat) results.

Inside (and outside) the madness of the tunnel.

Now if you found this post because you are looking to make a trip to a wind tunnel for yourself then you have my envy! Oh to be able to go back. So let me give you my advice (for what it's worth, which isn't a lot admittedly.)

- First thing, do your research. Read everything you can about it... check Slowtwitch, there are quite a few guys who have been and shared what they learned (Haycraft and TomA come to mind.) I wouldn't speak for them, but I think both would give you some good advice to maximize your time.

- Have the majority of your fit dialed in before you ever click on the website. You don't want to be figuring out your fit angles while spending $400+/hr.

- Make a plan. A detailed plan. Figure a run at 0° will take around 3 minutes, a sweep closer to 5-7. Then a few minutes to adjust something before the next run. If you have 1 hour, don't expect to schedule in 20 different runs.

- Test things in a reasonable order. It's pointless to find the best helmet for you, then change your position, because likely it changed when your position does. Imo test helmets last thing.

Don't do it in the reverse order...

- To echo John Cobb, save your time on wheels. It takes a long time to change them out and really... what are you going to learn... that 808's are better at 5° than 404's? If I could go back in time I'd have ran my race wheels in the tunnel instead of my box wheels, but it's not a huge difference.

- Verify your results and do sweeps, especially of the important things. Better to know that the things you did test are accurate and not an anomaly because you moved your head during "x" run.

Here's a link to A2's website to check it out for yourself.

Anyways, hopefully this was a little bit helpful. Always keep learning!

- Christopher Morelock

Trip & Review of A2 Wind Tunnel

 Where the heavy lifting is done

Recently I bit the bullet and decided to take my Aero loving self to A2 Wind Tunnel. Now, the first thing that makes people cringe when they hear you talk about "tunnel time" is the high price of entry. A2 is (to my knowledge) the cheapest of the tunnels available to cyclists, at around $420.00/hour. Not cheap by anybody's standards... but then, let's have a look at what kind of gains we are talking about for the Bones you are ponying up.

Grams of Drag going in - 2981

First Ride of the day

Grams of Drag coming out - 2811

 "Optimal"

Kind of like Floyd, but without the doping scandal or similarity to the green goblin

For those of you who haven't passed 1st Grade, that's 170 grams dropped. So Chris, you say, what  does that mean in "real world" terms.

Steve Hed (HED Cycling) would have you believe that you can save 3 seconds (in a 40k) for every 10 grams of drag you drop.  After some quick math, you (I) get 51" in a 40k, or around 2 minutes for a 1/2 Ironman. That's pretty ok considering I didn't have to do any more work for that... "Free" speed if you will, if you are willing to consider that $80/Watt is "free."

I'd say *most* people who went into a wind tunnel could expect to lower the cost/savings ratio by a substantial amount though. My position (the one I came in with) was one of the faster positions we tested all day. I figured as much, as I've spent A LOT of time doing independent tests to get to that point. However, as you can see, even I came away with some solid gains (and changes), and the peace of mind that now I know for sure what is "best" for me going forward. 

Now for a little more about the experience and what to expect.
The Wizard behind the curtain is David Salazar (the General Manager) and he runs a tight ship. This is what he does on the daily so you don't need me to tell you he knows what he's doing! We got pretty well down to business from the get-go. I chose to run stock wheels (instead of my aero wheels) per John Cobb's advice, and I didn't change wheels at any point due to it eating up time. (It's a bit of work to get the wheels changed, and, despite the numbers always being a bit skewed by the company showing theirs as "best" there is plenty of wheel wind tunnel data out there) I spent the majority of the time on hand position, pad width, bar height, bottle placement and helmet selection. These are things that are important and very individualized from person to person, so they are what I would recommend anyone taking the trip to focus on. For the most part you already want to have your position dialed in... making changes to bar height / width, etc is one thing, but re-doing your tri bike fit in the tunnel is just a massive expense for naught.

Jim O'Brien is the man who was called in for me to help with the mechanical/fit changes and let me just say, he is an EXPERT at what he does. Very knowledgeable with a wide experience base, but not so set in "his way" that he isn't willing to experiment or listen to your input. That's the exact kind of thing you want in an environment like this.

The experience itself is kind of "otherworldly" if you will. The outside of A2 is fairly unassuming, as is the town surrounding it. Only the race inspired street names (and race car trailers driving by) would give you any hint that something serious was going on around what looks like an industrial park. Once you come inside you are greeted by a very nice office, complete with plenty of pictures of exploits that can be at least partially credited  to time spent at A2... world record accolades aplenty. In the main "office" you'll see three computer monitors (Pictured above) where Dave does the technical parts. On the side wall are plenty of *toys* for you to test out if you didn't bring enough of your own. (tons of helmets, aerobars, hydration options, wheels... enough to make any tri shop proud)

The Buffet Line

Inside the actual tunnel, after securing your bike (watch your step!) and clipping in, getting the gear set for you to pedal in (you should cut all your cables before going in... they are just going to be in the way when you start moving things around) and a quick tutorial by Dave on what to be doing (and not doing... HOLD STILL) everybody exits and there you are, alone in the tunnel with nothing but a projected computer screen on the floor to keep you company. Dave then comes over the loudspeaker to tell you to get ready (I thought I was pretty witty when I replied "Yes God?" Sadly they couldn't hear me so I had to pretend like it was funny and move on) and then... the fans start! Let me just say... it's loud... and windy. Then, around 2 minutes or so later (You are pedaling the entire time, not *hard* but certainly at a healthy pace), your run is done and you can wait for Jim's either slight approval or complete dismay at the results, then it's time to change things and go again. After 28 runs, I felt like I had been beaten up on the bike... and my form was starting to suck (hey, it gets hard to hold the same position without squirming for that long) so that was the end for me. After that it was back to the main office to discuss what "it all meant" and what we ended up with, along with a Q&A where I spouted as many questions as I could think of. Then, it was off to re-fuel start the trek back home.

Dave, myself and Jim right after the last run of the day

 
So, wrapping up, is A2 for everyone? Was it worth it? Do you need to be a speed demon to get anything out of it?
I'll answer all of those questions with a question. How important is going as fast as your "motor" can take you in your next race? Personally I wasn't blessed with a big engine, but I want to be as fast as possible, so for me, it was well worth it. If you enjoy the local race or occasional big race but 2 minutes isn't going to make or break your day, then no, I don't think it's for you. The experience itself was worth the price of admission for me, I mean really, how often do you get to play in the same tunnel that Lance, Crowie, Drag cars and Superbikes (motorcycles) are in day in and day out? I mean... just look at the friggin' tunnel!

I had a joke about getting blown, but I'll let you be creative

How Awesome is That! I mean really, that thing is out of some Sci Fi movie!

For some extended reading on Aerodynamics (and testing) You could check out some of the following.

Here is my original thread on Beginner Triathlete
Bike Radar had a nice article on "How Aero is Aero" that is good for extended reading.
A link to the Chung Method Power model (for even cheaper home testing)

-Christopher Morelock