I have heard some good things about this tunnel, but not much yet. It worries me though when I see statements like the one about Steve Hed. Sounds like somebody is desparate for an endorsement, because when I called Steve last week, he was at the San Diego tunnel.

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Gerard Vroomen
3T.bike
OPEN cycle

The statement about HED... it wasn't made to me- to get my business. There was zero- marketing/push from them- they were super accomodative and helpful... this is the SOUTH - where people are laid back and friendly. I was talking with the tester (several hours into testing)- about lots of items... and I brought up various people- (he and I knew lots of similar people) and he mentioned the comment about HED- partly when we were talking about wheels (I happen to have HED wheels- and have Zipp wheels, too)... in no way- would I say this was to get business or whatever.... just a simple comment.... 3 hours into testing... I believe the guy- and you (and others) should give them a benefit of doubt. I was with a friend who had been to other wind tunnels- and although- neither of us has the ability to know how accurate any tunnel is- the place was really nice, and really well run (comment from my friend who's been to other tunnels...) and really fair on the time per hour pricing. It was my first tunnel experience- so I can't compare it to any other tunnel. But- I definitely see myself going back.

And my test was with your bike.... P3....!


And their tunnel next door- has years of experience testing Nascar... and my guess is their (Nascars) annual testing budget is way more than any tri/cycling wind tunnel budget.... my point- is that they've been in the business- and know what they are doing.... their main tunnel- for nascar (that's the only thing they test there) is open 24 hours a day- Monday-Friday... that should tell you something about the demand for their premier services....

No worries. As for us, our people have already looked into it, I think 4-5 months ago. Every time something pops up, we look at it, that's our job.

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Gerard Vroomen
3T.bike
OPEN cycle

I think they opened for testing in October 2007...

??? They've been around for years and in connection to the "bike tunnel" we spoke to them in September at Interbike. That's 4-5 months, isn't it?

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Gerard Vroomen
3T.bike
OPEN cycle

The A2 tunnel has existed for a number of years. Their development of a program for cycling/triathlon is new. I called them in the Fall of '06 and spent an hour on the phone with the person who was running the place at that time. It was clear he was an expert on wind tunnel/aerodynamic stuff, but he had a lot to learn about cycling and the kinds of testing protocols people would be looking for. But based on the dialog, I got the impression that this was the kind of person who was determined to learn about it and would be an expert in short order. He left me with a very good impression about what was to come. I left him with my phone number and I received his promise to call and to allow me to be one of his first customers when he had his cycling program ready to roll. He was looking forward to that being in early '07. Unfortunately, I guess he lost the number. (I didn't really expect him to remember. It was just pleasantries.)

Anyway, if the tunnel and their cycling program is any reflection of the character and determination of the individual I spoke with, I'm sure it's absolutely top notch.

To the OP ... thanks for the report!

.

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Bob C.

The "science" on any matter can never be settled until every possible variable is taken into account.

The smaller tunnell (newer tunnel) opened in Oct 2007. If they were talking about it before- at interbike- I don't know if they were actually up and running for bike testing... in that tunnel.

from your HED comment earlier....
Also- is it possible- since the Tour of California is going on- and HED probably had to make sure that all his Deep H3's and everything else were running fine for Astana- I could see him take a trip to San Diego's tunnel... since he' got to fly to Cali already... why not kill two birds with one stone... but that's just a guess....! Anyway- for anyone that hasn't been to a tunnel.... consider getting tested.... a great experience! And probably the best dollar/speed improvement you could make.

One of the guys testing me- was a former racing cyclist, worked with Team Saturn, has been involved in the bike industry for many years.... so they definitely have people- that understand what TT'ers/Cyclists/Triathletes are looking for....

Mark,

I've signed up to spend some time in a wind tunnel too. Would you care to talk a little bit about the methodology that you used while laying out your testing protocol. I. E. How did you design the order of the different tests? Where did you start first? How did you progress though the different set ups? Anything that you can offer would be of great help.

Mark

Be organized in your methodology... know exactly what you want to test. Test in order of priority... and leave yourself a little time at the end- to make on the fly modifications... Go over your testing protocal with tunnel staff....

Suggestions:

1- work on position first- this is by far the biggest element of drag... My bike was about 36% of the drag and my body was 64% of the drag....
a- such as- try from higher to lower positions- I had an adjustable stem- so it was quick changes from current set up- to 10, 20, 30, 40, 50 units lower- i started out slightly higher- and worked my way down- looking for any trends. Make sure you test your current position- so you have a baseline of improvement.
b- I saw someone else that had spacers- that were cut in half- so he just pulled out a spacer- and went lower- by 10, 20, 30, 40 mm, (he started out higher than normal- to see trends). Some people take cables off- to expedite tests.... time is money in the tunnel... you want to know what works- and you move on quickly.
c- try each stem position- with forearms/elbows- wide, medium, narrow...

What worked for me was slightly lower than current position- slightly more extended (longer stem) and narrow forearms... (I was already in a pretty good position) when I went even lower- it was more difficult to maintain- and it wasn't any more aero! I saw someone else- by raising their bars up from their current position and making their arms wider- like David Millar- was more aero than narrower and lower- and they might be more powerful/easier to breathe! Bottom line- everyone is different- there's no perfect rule of thumb!

doing the above- will get you to a good position- really quickly.... relatively speaking.

2- try equipment- I tried 4 different helmets.... - consider borrowing helmets for the tests- as aero helmets are not equal... and what worked best on me- does not work for others.

3- if you have different clothing options available- try them.

4- if you do triathlons- water placement- is mindboggling different- try front, frame, and rear mounts.... different systems- are very, very different.... p.s. that dimpled bottle that I asked about here: http://forum.slowtwitch.com/...ring=dimple;#1654692 I tested it and compared it to my specialized bottle- same 20 oz size- on the P3... downtube... quite interesting results, actually!

5- lastly- if you want to try wheels- try those last.... those make the least difference (assuming you have a good front wheel) !!! And when you try wheels- try front wheels first- as rear wheels- almost don't matter at all- if you have a TT bike that fairs the rear wheel well (I have a P3). A wind tunnel can't tell the difference b/t a 2k disc and $60 cover on a P3.....with a rider on the bike! but a 2k disc sure looks sexy! Now if the cover person invested their extra money in wind tunnel testing- they would probably be much faster ....

If you can bring someone with you- to help you wrench- that helps a lot- as the wind tunnel clock ticks away.... the wind tunnel doesn't like... and I saw others do some really interesting tests... basically showing- really cool parts- that look aero- might work or might be worthless.... yet people might be buying these things in droves ;)

Quick question. Over how many yaw angles did you test each position and equipment choice? Just curious...

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http://bikeblather.blogspot.com/

Sorry that we didn't get back in touch with you once things got up and running. Bob, the guy you spoke to back then, although he's still with the company, he's no longer part of our cycling program. If you have any questions or would like some info, please feel free to contact me @:
mike@aerodynwindtunnel.com or 704-799-1001.

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Mike

Sorry that we didn't get back in touch with you once things got up and running. Bob, the guy you spoke to back then, although he's still with the company, he's no longer part of our cycling program. If you have any questions or would like some info, please feel free to contact me @:
mike@aerodynwindtunnel.com or 704-799-1001.
Mike


No worries. I figured he probably scratched his head and tried to figure out where he put that note with the phone number of that guy he promised to call several months before. I can relate to that scenario completely. I have to clear mounds off my desk to find my desk.

I'm really glad this has come together and I hope it works out well for y'all.

.

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Bob C.

The "science" on any matter can never be settled until every possible variable is taken into account.

I tried 4 different helmets....

I realize that helmets are extremely sensitive to the rider and their position, but out of curiosity would you share which worked best for you? I am assuming that it was the rocket, since that's what you're wearing in the photos.


p.s. that dimpled bottle that I asked about here: http://forum.slowtwitch.com/...ring=dimple;#1654692 I tested it and compared it to my specialized bottle- same 20 oz size- on the P3... downtube... quite interesting results, actually!

STOP TEASING! :-) spill the beans... how'd it do? It's really a moot point anyway since the waterbottle you start with is gone in ~30 min anyway during and IM and then you're stuck with the 20oz Gatorade bottles (you didn't happen to test any of those... did you? ;-))

I would be more interested to know what the range of difference would be (and was it within the range that the tunnel balance can measure).

or, in other words...

is the difference measured from helmet to helmet within the uncertainty of the measurement.

also, would be nice to see an answer to Tom's question.



g

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greg
www.wattagetraining.com

first go around in the tunnel- I did zero yaw testing.... tunnel time goes really quickly.... adding yaws increases tunnel time- unless you are going to pay for 8 hours of tunnel time- I think testing yaws would be difficult.... if you want to do *lots* of tests.... I did 33 different tests.... the person I was with did 43 different tests.... that's a lot of testing (and a bunch of hours of tunnel time.

yes- the tunnel (A2) could definitely determine helmet differences.... I tested four helmets.... the pics you see of me was one of my first tests (you can see test #2 written on the wall)- don't read into it- whether it (helmet in pic) tested better or not.... and I'm not going to tell you b/c it's body specific..... truly it is.... just know that my worst helmet was 17 watts HIGHER in drag then my best helmet..... that's frickin huge.............!!!!!!!!!!!!!!!!!!!!! Knowing that one fact alone- if you've ever used a Powermeter- should be a reason to go to a wind tunnel...... Imagine doing a 1/2 IM at a pace that's 17 watts faster.... well- a good helmet can do that......the difference between a highly respectable front wheel verus another highly respectable front wheel at zero yaw was only 1 watt (this was tested by my friend). this wheel test was done with no rider- just race ready bike- and front wheel was swapped..... the tunnel was that accurate- and this test was repeated- same results. (by the way- every test we did in the tunnel is run 2 times.....for accuracy- with tons of data points averaged.... very cool stuff).

Unfortunately, that could also be why you didn't see much differences in front wheels. There's just not much difference between wheels at zero yaw. Go a couple of degrees off centerline with the wind, and it can be a whole different story.

Only testing at zero yaw is also most likely why you didn't notice much effect of a full disc at the rear.

I'm sure Doc C will chime in here on the dangers of testing at only one yaw angle....

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http://bikeblather.blogspot.com/

Hey Mark,

Thanks, but...

A. Unless you're testing at different Yaws then it's really hard to draw any sort of value from your testing. As I am sure you're well aware, 0* Yaw is basically non-existant in the real world and things perform VERY differently at different Yaws.

B. I think everyone understands that gear is highly individualized and that what works well for one person will not work for another. All you have to do is spend 5 min looking at the set ups of the Pros to see that. Lance, Cancellara, Leipheimer and Millar all have wildly different set ups - yet they're all highly tested and successful.

C. Finally - I appreciate that you spent good money to for testing, but unless you're going to share some of the results, even subjective ones - what's the point of your post? Unless of course you're getting commission for brining in new customers to the NC Windtunnel. ;-)

No disrespect intended... just sayin.

Brian

Brian's comments were basically what I was just about to post. The whole teasing bit with YOUR results seems a little silly to be honest.

You keep saying over and over again how different products have different drag for each person - sure, this is well known. The puzzling part of all this, is that you tested everything at 0 yaw. Don't you wonder if the items that tested well at 0 yaw would not actually test as well at other yaw angles. You may not have actually picked the fastest stuff in real world conditions?

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_______________________________________________

[/reply]
Unfortunately, that could also be why you didn't see much differences in front wheels. There's just not much difference between wheels at zero yaw. Go a couple of degrees off centerline with the wind, and it can be a whole different story.

Only testing at zero yaw is also most likely why you didn't notice much effect of a full disc at the rear.

I'm sure Doc C will chime in here on the dangers of testing at only one yaw angle....[/reply]

I've talked to the folks at HED before... and they have some type of calculator- that they've created from their many tests... I asked them if they've tested their wheels in a P3- they said- yup.... he's like- what scenario would you like to know... I then - said- say you are averaging 27 mph for 1 HOUR- with an 8 degree yaw... and what is the difference in time savings? The answer: Disc- would do save you approx 7 seconds over a HED3, and approx 13 seconds over a JET 90. So- yes- yaw does have an effect- I didn't say it didn't... but on a faired frame- like a P3- it's not all that important... Now- if the course is technical with lots of turns, accelerations- the heavier disc- might be slower- than a lighter weight HED3... rumor has it that HED thinks discs are overused- and they might stop making them.... how's that for your yaw!

I posted this- before I was going: http://forum.slowtwitch.com/...nd%20tunnel;#1658725 trying to get some insight- and the answers- after going to tunnel and experiencing improvements- the ansers to my thread were not very meaningful, nor accurate. I think I have given lots of insight about my testing. And I don't want to name manufacturers- of equipment- which worked/which didn't- with my set up- as I spent the coin- and it worked for my shape/body. The person that I went with- had completely different results.... I went slightly lower, narrower... he went higher, wider- completely different- but we both improved (reduced) our drag and now know what positions work for me.

As to the argument of zero yaw.... look at this thread... you can see- that Tom Danileson does his position testing- and it appears at the same yaw.... oh- if you look at the baseline- the Trek is MORE aero than the Felt- yet he tested better on the FELT... position is key.... I guess he doesn't know what he's doing either.... ironically- it was VERY similar to what I was doing with my testing.... (and I'm *very* happy with my CdA) :>)
http://biketechreview.com/...7013b5e6030f0f4cbfb6

this thread shouldn't be hijacked to talk about particular equipment- it's much more about proper positioning- and working with the equipment you may already own.... and the thread- above on biketechreview completely validates the positioning point. don't we all know that a deep dish or trispoke and deep dish or trispoke or disc in the rear is quite aero? do you really think you are going to gain- minutes by changing from a disc to a bump disc? but- you probably don't know - which of your 5 tri or cycling outfits are the best or several aero helmets you can get your hands on or if your position is totally dialed... or you hydration options- you wouldn't know this unless- you get to a tunnel.

I've talked to numerous people that have actually been wind tunnel tested- and rarely do people test yaw- b/c it adds time and great expense. If you have a great budget- by all means- test away!

I've got to back Mark on this one. If he spent the money, why should he just give out results which may or may not apply to anyone else. If you really want to know which equipment tested well for him, race against him. I'd bet that he'd even tell you which races he was planning on doing this summer.

Mark,

As for the number of tests that were completed, you must have had a very well choreographed and executed test plan.

My plan was to focus almost entirely on position. Thanks for the heads up on the split spacer idea. That will save me some time.

For helmets, I was thinking about borrowing a couple from the tri-shop that I work with. Unfortunately, they don't carry the Spiuk Kronos, so I may need to order that from a company with a good return policy. Just in case it doesn't test out well...Maybe Tom D. will send me one???? :o)

The tri-shop that I work with has done testing on different tri-suits before. They have one suit that they feel blows everything else away. I'm curious if you and your pal tried the same suits too? Did you both conclude that the same suit was the best, or did this follow along with the helmet findings?

My tri-shop has played around with all of the different water bottle setups and they have got one setup that they feel is the best. This was recently discussed here on ST, so there is no reason for me to go into it. I'm going to take their word on this one since it intuitively makes sense. I'd rather run additional position tests rather try and dispute what they've already concluded. My guess is that this was consistent between you and your buddy. Am I right here?

For wheels, I've got what I've got (Bontrager Aeolus 5.0's). The tri-shop will let me borrow a Zipp disc if needed, but I really don't think that I'll be buying one until after my divorce is final (I'm currently happily married and I'm pretty sure she is too, but a new set of wheels might change that). If I've got extra time though, it would be interesting to see the difference over the Bontragers. If there is a major difference, then a disc might get moved further up the list.

Mark

The funny thing is, of the 4 people who either replied or were mentioned in that thread, AFAIK none of them test at just zero yaw. Some may test at just one angle, but it's NOT zero.





Ummm...I think you may be reading more into that screenshot in that thread than is really there. If you watch the whole video, you'll see that what is shown in that screenshot is just the FIRST column of multiple CdA columns. I'll bet the other columns are at other yaw angles. Allen Lim is a smart guy. I'm sure his prediction model has an input for expected average yaw angle.

Oh...and on the differences in the tare values of the Felt and the TTX, what was the tunnel uncertainty again? ;-)




The truth is, if you're only going to test at zero yaw, you don't NEED to go into a wind tunnel.

It's possible to get just as accurate answers and you'll be much more cost effective with a power meter, an out and back course with a "dip" in the middle, a low wind day, and Robert Chung's "virtual elevation" method of comparing CdAs.

edit: clarity

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http://bikeblather.blogspot.com/