Heath and Brian. congrats on a terrific camp. We look forward to working with you a ton more!

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AndyF
bike geek

Really interested in any feedback on the Wing57. With visor vs. without. How did it match up overall. Camp looks great. A nice addition to bike fit options, well done.

The Wing 57 we had there was one without a visor. I believe 5 or 6 people tested it. It tested pretty well on some people and just ok on others. It was definitely faster overall than the wingspan though. Again, helmets are very individual, on one person it was close ( probably within the margin of error of the best helmet on that person).

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

I think the general consensus when talking about tests with the Rudy Wing57 fell along these lines:
a. It's consistently faster than the Wingspan
b. It's normally not the fastest
c. Overall, it seemed a bit underwhelming given the hype it recieved

Did you test any aero road helmets? And if yes, we're there any trends for relative rankings?

This is all very interesting. It sounds like a great experience. I would have seriously considered attending if it were within driving distance for me. Had any of the participants been to a wind tunnel before? If so, did this offer many additional gains or refinement?

Also, I think the additional attention to aerodynamic clothing for triathlon in the last few years has been really interesting. Were there any noticeable trends among clothing? I know sleeves have been getting a lot of attention recently. I'm just wondering about the differences between true TT skinsuits, aero tri suits, and standard tri suits. I'll be making a trip to the wind tunnel in the next couple months and I'm hoping to test out a few different clothing options, both for tri and TT.

Thanks for sharing your experience. It sounds like the gains that were made were well worth it! A 40 watt improvement in power output would take a lot of training.

A few aero road helmets got tested. The consensus was you can do a triathlon in them but they are not faster than a real aero helmet. iirc we nicknamed one of the aero road helmets "The Salad Bowl" bc that was it's best use.

An interesting find was we did have one person who's regular road helmet tested out faster than their aero helmet. We found an aero helmet that worked extremely well, much better than the road aero helmet.

I think the what was proven is a real aero helmet is substantially faster than aero road helmet.

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

The fast one is the P-09, yea? Awfully similar in shape & construction to the Scott Split.

A few people tested the Evade and it tested well for them but not as well as the best aero helmet for them. I did not personally test any aero road helmets. No one tested the LG or Giro since those trends had already been pretty well established. GENERALLY, the Evade>LG>Air Attack. Again it is very athlete dependant (splitting hairs too) and a good aero helmet is going to be better. The Evade and Giro do better than the LG if you are looking straight down. That being said, if you are looking straight down you are a danger to yourself and others. The suggestion was made that if on is to wear the AA to get it without the visor. Also the holes on the helmet where a visor attaches when not running the visor cause drag.

I tweeted this right after camp: Having a helmet sponsor is potentially a big liability.

The only way to know for sure is to cross your fingers and go with the trends or get tested. I think Jim mentioned in another thread the P-09 was the star of the show. But it was fastest on only 75% of the people. Not a bad trend though.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

Closer in shape to the McClaren. ;)

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

As Heath says and the reasons I searched out a good (consumer available) option last Fall, clothing is the next frontier in aerodynamic gains for triathlon.

Thanks. I even like the answer.

I did. I was considering one for crit/road races. I tested my (everyday road helmet) Giro Aeon against the Evade, Rocket, Wingspan, P09. The Aeon beat all but the P09. I guess Giro has a right to include it in their aero lineup. HOWEVER, there were a few surprising results in my tests. I am guessing that since I am a straight cyclist testing a TT position, some things may test differently for me than for others so keep that in mind.

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________________________________________________

Coach Brain: Accelerate 3 ; Incoherent Ramblings

Did you or anyone reach a point where going longer was better than going lower and were there any general guidelines if/when it occurred?

Any other interesting consistencies with elbow or head positioning that allowed you to go faster?

I don't think anyone had been to a wind tunnel before. Brian, Jim and I have spend time around the tunnel though. I will say my opinion is that this is a compliment to the tunnel and not a replacement. There are things you can do in a tunnel, yaw measurements for example, that you can't do here. Where this method excels is in real time testing. I've seen some crazy positions get setup in the tunnel only to be unrideable or nearly so on the road. It is immediately clear if that's the case on the velodrome. For example I pushed my extension 10mm forward and by the end of 3k my neck was killing me. Had it been faster, it wasn't, it wasn't sustainable.

Sleeves are good and ones that go to your elbow are better. The big thing is fit. You don't want wrinkles in the shoulder or across the front of the sleeve. Also it needs to be tight. The PI suit on Brian was slower than his 2 piece, it was neutral on Jack or slightly worse and awesome on me. Texture on the sleeves is a big thing as your biceps are basically two ugly cylinders, the texture helps trip the boundary layer.

Also I understand the drive/fly issues. Most people don't have the luxury that we do of the A2 tunnel being in NC and driving distance. I may schedule some time there just for pure validation sake. A2 is also relatively cheap at $500/hr compared to SD LSWT at +$1000/hr.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

clothing is the next big frontier imo. There are things everyone should pay attention to.

Like Wet suits it's all about the fit. The PI suit worked really, really well when it works and it kills you when it doesn't work. Poor fit = slooow and no I did not misspell it bc it was ~20w watt slower than baseline on me which was a 2 piece Desoto shorts and 2xU top.

The trends are texture especially on any cylinder shaped body parts (think arms). Sleeves can be good or they can be bad. Again we found that the trend is when it's bad it's really bad. Unfortunately a lot of people are going to be buying this stuff thinking they are buying speed when they are going to end up buying slowness.

we saw skin suits get beat by tri suits and vice versa, we saw aero tops and clothing get beat by standard kit and vice versa.

IMO the only for sure trend we saw applied to females. iirc every single one of them that sized down a size on their top ie a Medium to a Small reduced drag.

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

I tested both the Wing 57 and a Specialized Evade. The Wing 57 was fastest for me (by a slight margin) but the Evade tested very well on me. It beat the Wingspan and Selector I also tested. I couldn't cram the LG P09 on my melon since we only had a S/M but the Vortice was just behind the Wing 57 so they would probably be very close.

As for clothing, my CdA dropped in the Fusion top slightly but the fabric wasn't textured which seemed to make a big difference in some wearing the Octane suit. I unfortunately didn't test the Octane and am kicking myself for not doing so. Heath dazzled everyone with it on the last run of day 2.

This was a great camp weekend and I'm really glad I went. Jim, Bryan, Brian and Heath went above and beyond to help everyone there with position and testing ideas. I had always wondered about wind tunnel/CdA testing with the A2 tunnel within driving distance for me. I don't regret jumping on this opportunity which involved a cross country flight for me.

For me going longer was bad. I stretched out 1cm and it killed my neck and was slower. Me dropping 1cm was a big improvement. Brian was already pretty stretched out and had a super low CdA. 2nd lowest of the camp which is impressive given that he's 6'ish. A couple of the women testing were better stretched out and lower. It is really individual.

Jim says the trend is narrow, long and low. But not to much. Some people got worse when they went to low and started exposing their backs.

The thing for me is that I went to Jim for a fit and found out that I didn't need one as I done a good job on my own. I think I'd pretty much already gotten 95% way there on the fit. The only thing I changed was going 1cm lower in front. The moral is Fit first. Those that got in a good position got significantly faster in testing.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

I saw some gains by increasing my reach but I also made a few other changes that enabled me to do that. I increased my extensions up 5 degrees, anything higher was slower. I moved my extensions forward 1cm and I have no more room to move them forward. I run profile Tx's and they are the longest extensions. I'm lucky I have long arms.

The biggest thing to think about is your biceps are they are cylinders. Cylinders are typically slow. I'm pretty lucky, I have tiny biceps (actually not sure if that is lucky or not) and slightly longer than normal arms for a 6 foot person. I'm very comfy riding stretched out much more forward than your typical triathlete.

We saw tests where lower was slower, where higher was faster and slower. It's specific to the person. When I was with some athletes of mine at A2, the praying mantis position was crazy fast on one and elevating the hands higher was slower.

Just as wider arm pad width may be faster for some narrower may be faster for others.

The biggest thing the time at the tunnel and this testing taught me is that what you often think is faster is not and there where times where every single person was blown away at what was faster bc it defied all logic.

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

I pulled a picture from the article on front page to illustrate this:

http://www.slowtwitch.com/Lifestyle/A_California_Aero_Camp_4145.html#


The bottle sticking up looks like it would be slow. Jim walked down to the track and said, "Get that bottle off there!" It was the fastest set up. It beat a smaller bottle in the same spot and an xlab rocket bottle. Never ever would have called that one.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

De Soto Liftfoil and hairy arms? How am I doing?

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----------------------------------
"Go yell at an M&M"

Regarding suit fit, beside being tight fitting is the key point that the arms/shoulders MUST be wrinkle free or are there other aspects of how the suit fits that determines if it helps or hurts?

Thanks for sharing guys, it looks like a very interesting and cool camp to be part of!

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Fraser Bicycle | First Endurance

Check out my blog here | Twitter:@tmalis3

Not completely wrinkle free as that is nearly impossible. But if the sleeves are tight on your arms and held in place down low you will have a minimum of wrinkles. The sleeves were a bit baggy on Brian and very much so on Jack. That created a lot of wrinkles all down the front of the sleeve and around the shoulder area. That pretty much killed it.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

Thanks, that was my guess. First off all suits need to be tight fitting throughout so they don't flap around...then it would seem that additional or large wrinkles on the leading edge of the shoulder with "catch" the air and disrupt the air flow (kind of like an air brake).

As with all things aero, it's hard to believe how large of an impact seemingly small things are. Nice work to save all those watts; impressive gains!

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Fraser Bicycle | First Endurance

Check out my blog here | Twitter:@tmalis3

You forgot tiny biceps!

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

Just chiming in when I can between classes...

First off, I had an interesting and not too uncommon situation were my baseline changed. My "optimal position" was achieved during run #3 after rotating extensions up slightly and dropping 2cm with a CdA of .2447. I went back to this "optimal position" for run #8 and now had a CdA of .2512...uh oh. What I have done is assume that the CdA increased in a linear fashion between run #3 and run #8.

Pearl Izumi Tri Octane:

As you can see in the photo, I had a bunch of bunching and a ton of wrinkles on the shoulder and biceps. Surprisingly the suit actually tested neutral, 1.3 watt drag increase from optimal position baseline, and 1.3 watt drag decrease from "fatigue baseline". My theory behind the neutral test is that the sleeves were slow, but the fact that the rest of the suit was much tighter than my stretched out trisuit was fast. Plan: Tight fitting Kiwami coming soon.

Louis Garneau P09
The upset: The P09 topped the McClaren, although only by about 1/2 watt for myself. Another person was in the neutral to slightly worse when comparing the P09 to the McClaren.

Thanks for the info - this is great!

Any feedback on the P09 with visor versus without visor? I spoke to a couple of the LG guys at the Kona booth this past October and they said their testing showed it was aero neutral.

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Team Kiwami
Instagram

How did you determine your CdA was 0.2001? That seems low for a guy your size. What was your crr?

I asked Jim about this, and I believe he also posted it over in another thread, but he believed it was a slight penalty. I will strongly consider riding though as I hate riding with sunglasses, and I believe visor should be faster than no sunglasses. That's getting down to really small gains/loses though so I don't think it made the testing agenda of any riders.

it was .2006. you've not seen my very, very aero biceps in person, I assure you they are underwhelming even for a kid. My wrists/forearms are undersized as well.

I know we did a roll out & weigh in. As to the math, I try hard not to do math.

I'm pretty long/extended out front and narrow. My profile pad and mounts are modified to get the pads narrower than right out of the box. I think and I'd have t measure or find my fitting sheet which is in the shed, about 20mm more narrow then stock narrowness.

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

Did anyone mess with shoes?

Appreciate the response; agree with you that I would rather ride with the visor than with the sunglasses. One of the things I noted at IMAZ in November was that with the visor I didn't spend any time pushing my sunglasses back up my nose during the ride.

If that happens 2x per hour, there's probably a quantifiable 10 - 20 seconds savings over the course of the ride, which would equate to 0.5 to 1W savings :)

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Team Kiwami
Instagram

Skin is slow, wrinkles are slower?

One person did. They put some covers over the Specialized shoe and found them to be a bit faster. Shoe covers are weird. Sometimes they work, a lot of times they don't. That specialized tri shoe has a lot of bumps and ridges and holes.

As for testing different shoes, we all just "run what we brung".

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

Did anyone test the scott split helmet?

So when I was riding this weekend on box rims, 28mm wide cheap high rolling resistance tires wearing tights, long sleeve thermal jersey, wind vest, balcava and road helmet... so you never know... maybe that was optimum for me? My speed was not impressive for the watts i was putting out.

Pretty cool data. All I get out of it is that unless you can do accurate aero testing, it's a bit of a crap shoot.

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TrainingBible Coaching
http://www.trainingbible.com

It's a bit more than a crapshoot.

Putting a Torhans 30 on pretty much anything is fast...

Any data feedback on the Castellit top? Read lost about the PI Octane, but not the Castelli. Having seen the PI up close and in person, it just seems a heavy material that would heat up on the run in the sun.

Yep

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

No, still not available in the US yet. It has tested well for Nick Baldwin but YMMV. We just had the LG P-09 because I begged Jim to be Pierre at LG to get one to try. I'm glad I did!

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

Well not almost anything. It needs to fit close to the headtube. You had left already but it did not do well on my p5-3. It works VERY well on bikes with bayonet style headtubes. A Torhans 20 actually dropped one person's CdA down .01 on a Trek SC.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

We didn't have one to test, so no data. I didn't think the Octane material to be any thicker than what is on my Kiwami. I think they use cold black as well. At any rate I know of a several people who have raced in them without issues.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

Interesting.

Although if I was looking for front hydration with a straw, Torhans 30 would be first on my list. When it worked, it worked well.

Can you give any feedback or findings on the Fusion top? From the pics in the article, I see it was among the options tested.

My N=1; used my Octane on the run at IMAZ in November. Worked fine, though the temperature on the run was not extreme.

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Team Kiwami
Instagram

Thanks for doing this and for sharing so much valuable information. Yes ... there remain a lot of questions and a lot seems to be individual, but it's clear that it matters and some trends can be gleaned.

I noticed at least a couple plasma 3's. Wondering how the Torhans 30 tested with that frame in particular? I have that frame and was thinking about that exact hydration setup this season.

For some people it was neutral and it worked for one person. Here is that post.

http://forum.slowtwitch.com/cgi-bin/gforum.cgi?post=4943281#4943281


It is a really quality piece and I'm pretty sure that if you had a loose 2 piece on it would be faster. Most everyone at the camp wore tops that look like they came from baby gap. Tighter is faster. Get rid of wrinkles and flapping clothing.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

Thanks for starting this thread

Is your cda calculation based on what your individual power meter is measuring ? I assume so.

If so, is it safe to assume that your cda and my cda cannot be compared since one of our PMs may be measuring 10w more or less ? Or is there a way to compensate for this ?

I am very excited about this. With your CdA numbers (at 0 yaw) you can use bestbikesplit to get an estimate of drag numbers at other yaw angles. Granted these are approximate based on some more generic bike setups but more detailed equipment models are in the works. On another note how can I get this camp to come to Dallas we have a velodrome (outdoors though). There would be no problem selling out multiple days.

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-----------------------------------------------------------------
Founder: BestBikeSplit
Amazonian

No problem. It was a lot of fun and A LOT of hard work before and during and ongoing. At least we are into the fun part of it all though!

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

I'll try to get on here between clients today. And I'll try to remember everything as best as I can. Someone from the camp correct me if I'm wrong.

No one had the Split, but my work with Luke McKenzie seemed to confirm it's a fast helmet. The P09 worked on a broad range of riders - more so than most helmets. I don't think it really hurt anyone. It tied or bested the McCLaren on the few riders who tested both. Back in June/July we tested a prototype and found it faster without the visor. We also only tested it with the vent plug out, and at the speeds some of the campers were riding, it would've tested better with the plug in based on our previous testing (we didn't have a plug).

Lots of wrinkles are worse than skin, but a well-fitting tri suit made of the proper materials is very fast. I've said it before and I'll say it again...clothing is the next revolution in aero. I custom fitted tri suit would be awesome! wink, wink.

Booties are a crap shoot. Some are good...most are really bad. Only one rider tested booties (Pearl Izumi) and they worked for him.

Some riders found there is such a thing as going too low. Most riders perform better with added reach. Too many triathletes riding around with their arms perpendicular to the ground. Reach out further without losing skeletal support and you'll be faster and more comfortable.

There's so much more, but not enough time.

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Jim Manton / ERO Sports

The technology is getting there. I think pretty soon we should be able to test outdoors. AndyF will be able to give you a better idea of how close that is. He's probably sick of me bugging him about it (I think for a year now!). haha

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

Yes, I believe that is right. (paging AndyF.) We did have a case of a malfunctioning PM. Initially my cda was .27high. I'm a low watt model and go relatively fast on low watts. The numbers we were getting weren't jiving with the known data on me. After switching wheels, things started to jive.

we also used one wheel for a lot of the tests, in that case I think we might be doing an apple to apple comparison, but AndyF can speak to all of this better than I can.

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

I think I wore the fusion top the most during testing. As I said before, its tight but isn't a textured material so I think it provides limited improvement. My baseline was .242 and the Torhans 30 brought me down to .229 so that's when I put on the Fusion which brought me to .2252 so around 3w.

I constantly bother Andy too. Poor guy. It can be done with the system now, but it's not ideal.

To answer another question...yes, power meter accuracy is very important. On at least two riders the numbers didn't add up to what I was seeing, and both times there were issues. One was a pm reading to high, and another was a wheel rubbing slightly on a brake pad. We're very close to having clients only using our pm's to keep the numbers consistent across the board. It does drive home how important proper pm calibration is for everyone.

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Jim Manton / ERO Sports

Remind me on our call for Monday about a potential solution/fail safe on this. I've noted it, but it seems like we are going to be covering a lot of ground.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

so it sounds like the McLaren not being available pretty much anywhere besides occasionally ebay might not be too big a deal once the p09 starts to roll out, If I am reading this correctly.

re vertical arms..........I tried a more stretched position, but drag went up. might have something to do with my completely compact position(no where for air to get in) I will check this again sometime

Yep that seemed to be the case. The stretched out position did not work me either. I had already dropped 10mm and going out another 10mm killed my neck. I was happy it wasn't faster.

It is really amazing what 10mm one way or the other will do.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

I can't remember if anyone tested that with the plasma's. I didn't.
I'll skim through the plasma data and post if someone did.

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

I tested faster higher but have not figured out why I never implemented that.

so my post in another thread about BP 3.0 being faster than 2.0 based on castelli's marketing hype might have some validity if they really did add texture in specific areas

Yeah I would say so. It seems like from what has been constantly observed, texture is faster at least on the arms. That being said Jim said that the Castelli suits have always tested very well.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

it was tested on a Large Plasma. For that particular rider a standard BTA tested better than the torhans 30. The BTA was < 1min faster, closer to :40 really at 200w.

But unless you ride like that rider it may test out different.

The #1 thing I would caution everyone is that these results are specific to the individual that tested. You results could be worse or better. There is no real way to know unless you test. We can make some inferences but not firm conclusions from a rider that tested to you.

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

On average, how did the Giro Selector fare?

As a general take-away, if you were to do-your-own "Chung-ing", what would you look to test/iterate through? I'm also wondering how well a 2 state (high/low) multifactorial design of experiments would tease out maxima/minima given the nonlinear interactions between different setups (e.g. a helmet may do terrible with flat forearms, but then becomes the best when you mantis).

That said, the more variables I can eliminate, the smaller the test table gets. As it stands below, it'd be HUGE to test every combination. Obviously I'm $$ limited on what goodies I can test as well, albeit with a lot of tri-friends, I can probably muster a lot of equipment. :) When I find myself doing fits, I usually trend towards Andy Coggan's "caveman" fit suggestions. Looking to get smarter than that.

* Hands/elbows
1.) Higher/lower
2.) Further/nearer
3.) Flat vs uptilt forearms
4.) Narrow elbows vs wide

* Helmets
* BTA setup vs nothing vs ?
* Clothing

Am I missing any variables? Any that I can safely "assume" are linear in their interaction with the system?

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The question of who is right and who is wrong has seemed to me always too small to be worth a moment's thought, while the question of what is right and what is wrong has seemed all-important.

-Albert J. Nock

Two questions...

1) Any wheel or tire tests done?

2) When are you guys doing this again? :) I want in!

Pretty darn good. It was the 1st or 2nd fastest helmet on most people. I'm including the Bell Javelin since it basically the same lid. We used the shield based on Jim's recommendation.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

We try as often as we can to use one of our powertaps. This ensures that we have a calibrated power meter that we know is properly calibrated. And that the drivetrain efficiency is no longer a factor.

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AndyF
bike geek

Jim can probably give you a bit better answer than me. But get the position first then find the helmet. In other words, if the Mantis is the best with the baseline helmet, test other helmets to see if it works. The mantis is one of those that doesn't work on a lot of people, but when it does, it works very very well.

Hands level or just above the elbows.

Position, helmets, clothes. At some point you just have to decide what to test. I didn't get to test everything I wanted because I ran out of time. I think a lot of us were like that. If you are field testing maybe set aside one day for each thing. Day 1 Positions, 2 Helmet, 3 clothes. That what I would do FWIW.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

Awesome. Thank you.

As you said, we work in a time-limited world, so trying to catch the biggest fish is the goal.

And big thanks for all the Q&A!

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The question of who is right and who is wrong has seemed to me always too small to be worth a moment's thought, while the question of what is right and what is wrong has seemed all-important.

-Albert J. Nock

Chris, hope everything is going well up in the valley of the sun.

No one tested wheels because we are testing a near zero yaw. Everything does well.

Again? Ask me Tuesday. But I think given the number of emails Heath and I have gotten there is strong demand for rolling this type of aero testing out.

You have to realize this was the first time it's ever been attempted, to do something like this on this scale and do it how we did. We all need to sit down and chat.

I know, and I am pretty sure I can speak for Heath on this, and possibly Jim. If we can figure out some things, there is no reason why we can't do this again except for maybe some national teams wanting their velodrome back.

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

What if there is 90-100mm from the back of the T30 to the front of your headtube? I'm on a 2011 SC 7.5 and that's as close as I can get... plus, I still have a standard Ultegra brake (haven't upgraded to TriRig yet).

Edit: did you test the T20? I know Dirk Bockel runs that and I've heard rumor its because he can't get it (the T30) flush with his headtube.

Our pleasure. The big goal is letting people learn about the process and realize the individual nature of the testing. The other big one was showing that age groupers, not just pros, can and will benefit from this type of thing. Combine this with good training and coaching and you have a lethal combination.

I was talking with Jim on the first night I was there about why people don't do this more. His comment was that a bike fit and aero testing aren't made of carbon fiber. Haha! I might be paraphrasing a bit, but when you consider testing even at SDLSWT at $1000/hr or A2 at $500/hr is a relative bargain compared to a ZIPP Super 9 Carbon Clincher at $2500. The Zipp might save you 10 secs over a wheelbuilder cover, but the same money or much less in our case can potentially save you minutes. Knowledge isn't Gucci or Prada, but Carbon wheels are.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

Well there's the bling factor and the part that it just takes a lot more mental and physical energy to pin down one's position/stuff rather than swiping one's credit card. Much less using minding one's P's and Q's on using the Chung/virtual elevation method in a controlled (and worse in an uncontrolled) environment.

Me? It's not an either/or! I'm working with a wired ptap, much less tunnel time or superwonderbling. :) Virtual Elevation and a stopwatch are my only way of testing things. :)

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The question of who is right and who is wrong has seemed to me always too small to be worth a moment's thought, while the question of what is right and what is wrong has seemed all-important.

-Albert J. Nock

I would also like to add that rules of thumb will get you a long way.

I've never tested anything but just went off the ramblings of the gurus here and my base run (current setup, no changes) was .225.

Once I started making changes, the lowest I saw was just under .220...like .217 or something and that was simply from going from a Med to a Small tri top. I tried all kinds of things but my massive (chick magnet) guns would just not allow me to get much lower.

I was also not willing to change my fit for the testing. I've tried going lower and it was unsustainable so knowing that fact really sped up the testing process. I would say before going testing, figure out what you are willing to change first regardless of aero or not as it will save a lot of time. I've worked on my fit for some time and know what works and what doesn't.

BUT....some huge things I learned was what hydration setups were neutral and what were not. I was able to test a ton of different setups and figure out what options I had available to me without impacting me too much. That was SUPER info to have. So it's not always about lowering your CdA a bunch but often what impact different decisions in your setup have.

I was also able to validate my current setup. Oh...and I learned my skin suit for time trialing was SLOWER than my trip top because it fit like shit. It was the smallest size I could fit into. BUT, it still wrinkled in the shoulders. So, because I have to ride in a team kit, I only have two options, tri top in a TT (which is lame) or have the suit custom tailored.

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Wattie Ink Triathlon Team
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It is funny you say that, because that exactly the way this whole project got started in the first place! VE works, it just takes time like you said.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

You could always get a new team with better clothing?!?!?!

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

I started with a wired Power Tap so I didn't even need a stopwatch. A Power Tap is perhaps an ideal tool because you don't have to worry about drivetrain losses. But it's absolutely true that a wind tunnel or the great setup at VSC will be faster, in part because the environment is more controlled and in part because there's someone to guide you through changes -- I had to figure that stuff out on my own by trial-and-error-and-trial-and-error-and-error-and-error. And, doing this kind of thing in a "camp" setup where you can see lots of other people testing can be eye-opening. It really hammers into your head that things that work on one person don't necessarily work on someone else, and that the eyeball is a poor wind tunnel. It's humbling when you realize that everything you know is wrong.

Well, I meant race results by stopwatch, but that's neither here nor there. :)

I'm lucky enough to be able to borrow from your (and other early adopters) efforts and try to improve on them. We'll see how that goes. :) But it's assuredly not for everyone.

Thanks for the work thus far.

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The question of who is right and who is wrong has seemed to me always too small to be worth a moment's thought, while the question of what is right and what is wrong has seemed all-important.

-Albert J. Nock

"Two of the camper lost nearly 45 and 67 watts of drag just due to position alone." Holy crap!

"My CdA went from .2643 down to .2267" Congratulations, that's a big drop!

Sounds like an awesome event. Too bad it's on the West Coast, hard to justify a trip all the way across the country. Will have to stick to "Chunging" it!

You mean, not everyone has the patience to do this on their own? Yeah, I agree.

Besides Heath and Brian and AndyF and Jim Manton and the folks who went to the camp and have been willing to share their findings, you should also remember to thank Tom A. and Alex Simmons and Adam Haile and a bunch of guys who showed this stuff works at an early stage when a lot of others were skeptical. I'm pretty far down the totem pole.

if you were looking to upgrade a helmet, i understand it would be a bit of a crapshoot, but based on what you have seen, would you say the LG 09 is better than the wing 57?

I don't know if Heath will say it, but I'll say yea that the odds are likely in your favor.

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@adamwfurlong

I think this is a great idea and something I would considering doing for sure but I have a question about experimental methodology.

The environment being used is highly controlled (I appreciate why) and -- I'm assuming -- the athletic efforts during measurement are short and free of many real-world factors. Riders will be highly conscious of being the subject of study and therefore will more than likely be on their best behaviour. How do you control for that difference so that when these equipment and position choices are taken outside they're still optimal?

What I am thinking about mostly is changes in posture over long efforts; form frequency of head-dipping to fatigue related postural changes.

[removed an embarrassing comma!]

interesting! thanks :)

You control for that by hardening up and not letting your form slip. Observe - Tony Martin, and Keinle, and Rapp

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Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

on my test, the first thing we did was go wider on the aero/elbow pads. The made a signifigant drop in CDa. It's not clear whether or not that particular change became aero or if it became more stable and less wobbly which inturn made me faster with less drag. Move the pads out was a definite shocker to all.

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Well, first, that's something that can happen with wind tunnel measurement, too. Second, one of the virtues of field testing is that you can often tell whether your position is sustainable for the targeted length of your event; third, even if you can't hold that position for the whole time, the times when you can hold it will either be faster for the same power or require less power for the same speed, which can help your run; and fourth, sometimes you have to just HTFU.

it did not test well on most. In fact it added drag even if it wore pretty wrinkle free and tight.

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I love these kinds of stories. The eye is a poor wind tunnel.

it was a crap shoot. The Torhan did not test well on me with the Scott Plasma, but did test well on others. The Torpedo tested better on me than on others. With the bottle and bike frame it appears to have more to do with the body composition of the rider than the bike frame.

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each run was 12 laps or so. The first 2 laps were getting on the track, up to speed and zeroing out the PM. The next 10 laps were the test. Each lap was 250m. 4laps =1km and they were ridden sub threshold but not social ride pace. Do 8-13 runs and you're getting a decent workout. if you weren't in decent shape the testing begins to take a toll. I know on run ten I was thinking this is fun and this sucks. On my 13th run I was thinking this sucks but at least I'm learning a ton.

If it's a sub optimal position, as when reach was extended out, or stack lowered too much, just like if you dropped 20mm off your stack, you know fairly quickly if it's doable or not.

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

Hmmmm, interesting. I thought the T30 would be good to go on virtually any frame as long as it was flush to the frame or at least very, very close. I didn't think about the rider at all. This thread is really beneficial, thank you to all who participated

Not sure if you were around when I was testing, but I also ended up faster with elbow pads out. Allowed for a much more natural and sustainable shrug as there was room for my spine/neck to relax between my shoulders.

define starting width and ending width, i think this context is important...............

fyi i had tunnel results in the past that(even with the noise of my holding same position)consistently show narrow is much better for me. the caveat is that my narrow and a lot of triathlete's narrow are not the same definition. at 11cm c-c as base point +2cm= 12w hit , +4cm=18w hit +8cm =14w hit. so, going wider was starting to get faster, yet it was so much slower than going really narrow that it was a non-starter for me. I now have teh means to go wider yet so sometime i might try to field test that to see if anything helps. i should add that at 10 deg the +4cm was faster by 3w but given that most of teh time i will not experience that deg of yaw, it was not worth any consiration or exploration. I saw similar results for the other fellow with me. we had to tape his arms together as his pads were too wide and he was having trouble due t that in keeping arms together. narrow in this conotation is forearms pressed together, no gap

for 80% of the people, the P09 was the helmet. No other helmet came close to that sort of success rate.

If you are going to bet on a helmet without testing, your odds are pretty decent betting on the P09. Not 100%. It either worked or it didn't work well, but it worked for a lot of people.

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

I agree with the above. I was at this event as well and my lowest drag numbers was achieved when I shrugged. Low drag is nice but shrugging like I did is not sustainable over 56 or 112 miles. However, knowing that shrugging benefits me allows me to use it selectively. On flat and windy sections it is good to know that if I suck it up there is a good rate of return.

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http://www.frostyjunction.com/
https://twitter.com/FrostyJunction

I looked through the pictures and didn't see any, but did anyone have a Giro Advantage or Advantage 2? Those helmets seems to always pop up at track World Cup with teams that presumably have access to testing facilities. I tried one against a Selector and the Selector was 7-10 Watts slower through a range of yaw angles.

Most of us tried the A2 and it tested overall well. It seems to be a nice "go to" helmet if you don't know what to use. The A2 w/o visor tied with the Javelin w/visor as the fastest helmet for me. It should be noted that the A2 was a size medium and the Javelin a large. I think a medium Javelin would have tested a little faster on me.

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https://twitter.com/FrostyJunction

After the P09, it probably tested as the most consistent fast helmet for a wide range of people. EDIT: I'd have to go through all the data to make sure of that, bet I'd bet $10 and a beer that that statement is correct.

When Heath and I were at A2 this past summer we chatted with those guys. They said the A2 was a solid choice for the majority of the people they test, almost always in the top 2-3 helmets. We also found that to be true at the velodrome. But again, many aero helmets that were really good on 2,3,5 people were really bad on 1 or 2.

I know if I run across an A2 that fits, even though it's the 2nd fastest helmet for me and I now own the fastest, I'll probably scoop it up just in case.

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

Yes that is ultimately good advice but Tony, for all his quadricep might, only rides for the better part of an hour. Limited duration being part of what makes ITT and TTT such a strict discipline. I am thinking of, say, AG triathletes interested in optimising their bike leg and must be a large component of the potential market. Its absolutely great that each person can obtain objective information from the camp. I was just curious if participants think about how they actual ride in races vs what they do when getting their photo taken -- so to speak. :-)

This thought was just spawned from the interest in fast helmets and how often some people I see training dip their heads.

I am not sure where you are trying to go with this? Naturally everyone will be fatigued after 112 miles. For the testing to be accurate we need to control as many variables as possible. I don't know how you would perform a test where each run is let's say 2 hrs. I did about 10 runs. At 2 hrs per run I need to quite my day job and setup camp at the velodrome :-). I am not sure what the alternative is.

I feel I can hold my second fastest position for the majority of a 112 mile ride. For sure I can hold it for 56. My fastest position is when I shrug and I know that is not sustainable. Even if I could not hold my second fastest position for the full length of the bike leg what we learned will still be beneficial. As long as I am holding the position that tested well I am benefiting. Lets say at some point I can't hold the position any more that does not mean that everything is lost.

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http://www.frostyjunction.com/
https://twitter.com/FrostyJunction

Sorry if you already answered this but was the P-09 generally faster than the Air Attack even for the head down guys?

I know that none of this information is universal, but it would be pretty cool if there was a ratio of elbow pad width to shoulder/hip width that could be collected to see if there is an optimal number.

A couple of slightly off-topic takeaways...
1. It was great to put faces to Slowtwitch names - made some new friends, and had a lot of fun.
2. I honestly think that, when possible, pro triathletes should not seek helmet sponsorship, but instead figure out their best helmet and then sell the space for advertising. There's at least one big name pro doing this for 2014, and I know it's far more lucrative for her. Not my idea, but it's a good one.

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Jim Manton / ERO Sports

I think you hit the issue on elbow width. A number of articles discuss this. Elbows wider with bigger guys to allow air be deflected around hips and legs.

I got the exact same result when I tested it at Faster wind tunnel after Ironman Arizona. I would still consider it on a cold day as it has probably less penalty compare to adding a jacket or something + you can swim with it so quicker T1 possible... but I will never wear it again on a warm day... what a mistake I made at Ironman AZ...

There was a lot going on in his reply to you.

Bottles on the frame: results varied based on rider. For one ride a round bottle on the downtube barely moved the needle for another on the same type of frame, it was negative.

Torhans 30: This bottle did very well on bayonet style frame and not as well or worse than BTA bottles on rounder head tubes. I would say a big majority of the reason why is that we could not get the bottle close enough to the headtube.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

The only time the Air Attack MIGHT be faster is if you are riding so head down you can't see. In other words looking at your down tube the whole time. The air attack is an aero road helmet and not an aero TT or Tri helmet. By Giro's own marketing it is 9-12 watts slower than the selector and about that much more over a very vented road helmet. That has been shown to be accurate in testing.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

Pity the P09 isnt available here in aus. I sent an email to the local LG distributor and they replied:
This helmet is currently still under development. We met with Garneau at the TDU to get further updates on this helmet. There have been further improvements from the P09 helmets that were unveiled at the Hawaiian Ironman last year and as such, the helmet has not yet gone into production. We are planning on having the P09 helmet as part of the Australian collection if it meets all the passes all the Australian Certification requirements.

At this stage we do not have a confirmed delivery time for the P09, however I would not expect it to be available any earlier than November. Putting a helmet through Australian Certification can take many months before the helmets are given the green light for Australian delivery.

One of the coolest parts of the new Specialized tunnel is that they CAN run for as much time as they want. So if an athlete needs to test how sustainable a position is, they can.

Tangential, but sweet nonetheless

It sounds like the T30 would be a good route if you were able to get it flush with the head tube. That is my plan, if its flush, I'm using it, but if not, BTA it is.

That is pretty cool. The only issue is getting in it. I guess if you are Specialized sponsored athlete it is not that tough. Most of us are going to have to use the alternatives.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

Very true, not a good option for the 99%ers

HEy Jim and everyone else! I am curious what hydration setups you tested. Mainly in front hydration. I know that the the Torhans 30 is dependent on how close you can fit it to the headtube, but how does it compare to something like the new Xlab System.

Also, did anyone test the new castelli top?

Very interested in finding out more about the results for a round bottle on the down tube. What was the worst result observed for this scenario. I have read that a round bottle on the down tube costs something like 1 s/km and that an aero bottle in the same position cuts that in half. Obviously this number would vary based upon design of the frame (e.g., the newer Cervelo frames are designed to help shield a bottle on the down tube) as well as rider position. If the 1 s/km number is based upon testing a bike with no rider on it, then it would seem logical to expect this number to decrease with a rider due to the rider's legs shielding the bottle.

Wow, I'm just blown away by the response this thread has gotten.

As Heath and Brian have mentioned, this was first of its kind for aero field testing. Our aim is to bring aerodynamics to the 99%. Aero testing is more accessible to the AGer now than ever before. We are seeing people improve their times significantly after just one session.

And, contrary to what a lot of people imagine, it works for fast and slow riders. It's certainly not just for pros anymore

What Heath and Brian have done is simply to have a party where everyone just gets faster. A cool idea, and one that we're very happy about.

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AndyF
bike geek

The data we have would be specific to the bikes they were on. I doubt we had enough bikes, especially since the Scott Plasma (n=4) and Speed Concept (n=2) were just over 50% of the bikes there, to draw conclusions that a round bottle is neutral on Bike brand C or Bike brand B.

Also we saw different things happen on the smaller frames vs larger frames. It could be and I don't have enough testing time or data, but it could be that as you scale up in frame size the bottles have a different effect bc they don't fill in as much of the gap between the BB/Down tube/seat tube junction.

We crossed off a lot of questions during testing. But the testing generated as many new questions as it answered for many of us. We are now into the upper low low hanging fruit vs just picking clean the low hanging fruit.

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

Different people tested the X-lab, Speedfill A2. Torhans, Profile aerodrink and standard BTA

As with everything it varied across the board. The Xlab worked well for several people but was slower than a standard BTA for me and one other person. The Torhans worked very well as long as you could get it close enough to the headtube. The speedfill, while a cool design really has a lot of stuff sticking up off of it with the fill cap and straw. Due to that it was not horrible, but never was the fastest option.

With hydration you aren't trying to make gains you are trying not to lose them. So ideally you want whatever you put on your bike to be neutral.

No one had the Castelli speedtop. It would have been interesting to see if it lived up to the hype.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

I cannot believe nobody asked this question yet. Cost?

Replying to a few questions at once - yours first:

I know this gets old, but it's very athlete dependent. The campers can chime with their individual results, but the Torpedo works on a broad range of riders and, unless I'm mistaken, was the best overall bta setup - some found a regular bottle faster, others the whole system. Campers, am I wrong that no matter what the BTA bottle, it was an XLab mount? For hydration, it's more than just aerodynamics (gasp!), which is why I like the Torpedo even more as a system with it's adjustability and ease of use. Love the computer mount up front for both visibility and because it hides behind your hands. There was one test with a computer mounted on top of the bottle and that wasn't a good performer. Of course, that all depends on how high the bottle is sitting above the extensions, too. In other words, if you're going to have a setup like that, you should work on getting that bottle low so the computer isn't sticking up above your arms.

Surprisingly, no one brought a Castelli T-1.

Downtube bottle placement is not only dependent on the frame, but also the rider. Very difficult to predict.

Andy, it's even more true now than ever before that speed doesn't matter for anyone who wants to take advantage of aero testing - heck Desert Dude's power meter has been lying to him for who knows how long, so he's much slower than he thought! :-)

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Jim Manton / ERO Sports

With the long hours and jet-lag my head definitely felt like we had a big party. The good part is I remember everything after this party!

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

A lot of people used the X-lab setup. I actually had my own cage ziptied to the armrests and didn't use the X-lab. I think you can be safe and do that, unless you just really want to use the x-lab mount. I think we may have used electrical tape to attach different bottles for one person. It is kind of blurring together right now.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

If you click the link for the camp in my sig line it is all there.

We are debriefing with Andy and Jim on Monday so that it subject to change.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

No one was that narrow. It would probably be hard to hold going around the track too unless you had practiced it a lot. I was one of the more narrow people at 18cm c-c. The thing to remember here is that everyone but one person was a triathlete. Getting that narrow for a 40k TT is fine but would be tough for 90 or 180k, especially after swimming.

I'd personally like to test that narrow just to see, but again time caught up with us, and I'd only use it a few times of the year at our local TT's.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

Ain't it cool? Or, in my world, "the purpose of models is not to fit data but to sharpen questions."

JTolandTri and relentless:

Quick elbow position follow up questions...

I seem to remember John Cobb stating that broader shouldered athletes often do better with wider elbow and hand placement. So, How would you describe your shoulders, arms and chests - skinny, broad, big, etc.? Did you keep your forearms and hands parallel (hands apart) or angled (hands together or close together)? And, how were you forearms angled - flat, upwards, etc.?

Thanks.

David K

my aero bars are fixed width and the aero pads can only be adjusted to one of 3 positions (vision set-up intergrated). My base test was set to the middle position. The improvement gain was made when we set the pads to the outside positon.

I think this is the benefit of non wind tunnel testing. Wind tunnel testing doesn't take into account rider stability. Going wider made me more stable and thus faster. I'm sure in a wind tunnel this would have made me slower possibly, at least that's what conventional wisdom dictates.

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It's awesome and completely sucks at the same time!

The not knowing what I don't know is killing me especially since I now know the questions I want to know answers for.

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

I used the Advatage 2 for base testing. It was the 2nd fastest helmet for me. Only the Bell Javelin was slightly faster.

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I dig the picture of Taylor on the track and Andy on the apron in that pic in the link to the next camp!

Sorry to go OT.

damn that "looks" aero, but is it stable? Stability > aero out on the road IMO.

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I ran with one bottle on my downtube, then swapped it out for a BTA... and my CdA increased by .0089

JT is long and lanky. He's like 6'4"and weighs 140lbs. I'm 5'10' 167. I'm just about as skinny as its ever gonna get. I've got wide hips which are apparently in proportion to my upper body.I don't consider myself a big guy, but apparently I have broad shoulders and a broad chest. My aero bars are J- bends. From my elbows to my finger that are angled inward and not pararell.

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Rather than look for reasons not to get aeroashell, look for ways to make aeroashell work.

Usually it isn't even hard you just have to try.

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Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

Cool stuff! My question is how you controlled for keeping bike position constant between runs to isolate the difference in each change you made? What I'm getting at is that to find out if a bottle or other equipment changes(and some positional changes as well) makes a difference, the bike position needs to be very stable since relatively small changes there might skew the results a fair bit. Holding a position can be hard enough in a tunnel where you're stationary, and have visual aids to help you, so I imagine it must be significantly harder on a track. Especially with most people probably not having much experience riding on a track at all before testing.

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BA coaching http://www.bjornandersson.se

>>for 80% of the people, the P09 was the helmet. No other helmet came close to that sort of success rate.

For what kind of head position? A triathlete's, aggressive TT or both?

We made one change at a time. So we never, for example, lowered someone AND changed their helmet. We just did it in isolation. If it didn't work we would go back and change a single variable. As far as having someone hold an exact position, that was going to be hard as you said. But no one was going full gas and from what I saw when we would re-baseline, the runs would be withing the margin of error. Towards the ends of all the runs there were definitely some throwaways as people started getting tired and drifting.

No system is perfect which is why I think this is a great compliment to wind tunnel testing. In the tunnel you can get away with some crazy positions that might test fast but be unsustainable, on the track it is pretty obvious right away if it something you can hold. The model has been validated enough by people like Robert, Tom, Alex, and Andy, that we feel pretty confident in the results we got back. Like Brian said, more work to do and more questions to be answered.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

David-
As relentless already chimed in, I'm on the lanky side at 6'3" and growing while topping the scales at 148lbs.

I started at what I would consider a moderately narrow position, but still enough room for a comfortably mounted BTA and ended up about 2cm wider than that. If I had to guess at what caused my drag to go down I would link it to this: My arms are skinny enough that it really doesn't matter what they shield and when I brought elbows apart my upper back and neck naturally (w/ no effort) shrugged allowing for much lower profile. I would have liked to test a "super" narrow pad position as I have ridden comfortably like that on the road before, but did not have the ability to rearrange aerobars for that while testing. I certainly plan on field testing that in the future though. I would not contribute that drop in drag to stability because narrow is my standard riding position. Somewhat head on shot below of elbows narrow:

Bjorn-
Interesting question and certainly one that is on my mind. I did run across the problem that my baseline from run 3 and run 8 were significantly different. This put some limitations on the data I have, but I can still compare 2-3 runs either side of both baselines, which covers pretty much everything. I would argue that it may be smart for a triathlete with no experience on the track, etc. to do more than just a starting baseline, maybe baseline as frequently as every 2-3 runs if you are trying to isolate small changes like hydration.

Also, counter to what Heath just said, I did go for some double changes as I started to get desperate for some drop in CdA near the end. I did a test of Rudy Wingspan and P09 with elbows narrow (head more "popped" up) and then repeated the tests with Wingspan and P09 with wide elbows (head naturally dropped and turtled) and the P09 crushed the Wingspan. I didn't even make it more than 2-3 laps with the Wingspan before Bryan concluded it was not worth continuing. It seems that the Wingspan has been a generally good helmet when your head sort of sticks up, but once you can get one of the rear ported/long tail helmets sitting nicely on the back they are quick.

very stable, I go through turn in the bars, ride them in the wind, etc. have ridden up to 80 miles this way, no need as a cyclist to ride further than that ;) I'd imagine after a swim, shrugging might not be happening so well, but there is no issue in holding that for long periods of time of at vo2+ level efforts or climbing. at least not after a small amount of adaptation. I might not want to do this if my position were extended much. one thing I have found is that is that it is much more stable with head down even when very windy out. conditions that if head were up(warm up or general riding) I end up getting blown around, but when I drop head and shrug, smooth as silk like it smooths out the flow and creates my own little cocoon which isn't disturbed by passing semis in 15-20mph winds

side benefit is that I have the entire base bar available for climbing steep hills if need be, like I might on a road bike and not relegated to aero or horns. that and basebar gets to see more clean air

drawbacks include no BTA and cpu under arms( and with age also comes lack of up close vision so...), but with narrow wrists, it can be read between them :)

I have done a couple of TTTs like this without any complaints

I was a bit nervous about the repeatability and had the same concerns. I in a way got "lucky". It turned out that my original position was the fastest. Run #1 was my baseline run. Then as I started changing my position, lower, higher etc my drag went up fairly significantly. I was thinking there was something wrong with my baseline so I went back to the original setup and I was back to my original drag number. I think the reason I was able to repeat the run so well was because I have ridden the same position for two years so it feels very natural. I think your point is valid. If my new position would have been very different from the original I think it would have been hard for me to repeat as well as I did. Hopefully Jim or Andy will jump in and address the repeatabillity issue.

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Relentless was not looking for a way not to get "aeroashell". He attended the camp to get "aeroashell". It so happened that wider tested faster for him whatever the reason might be. The stability thing is just a theory. He nor anyone else knows exactly why it tested faster for him.

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http://www.frostyjunction.com/
https://twitter.com/FrostyJunction

My gratitude isn't in exclusion to anyone--you just popped up here. I remember well here and on the Wattage group when this stuff was first getting vetted. Didn't have a powertap at that point to play around (nor felt comfortable with R/python)

I really appreciate the discussion and absorbing as many takeaways as I can--from all parties.

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The question of who is right and who is wrong has seemed to me always too small to be worth a moment's thought, while the question of what is right and what is wrong has seemed all-important.

-Albert J. Nock

this +. please

Hmmm. The answers to your questions are actually kind of complex. The overall issue is related to an analysis of variance type model where you're trying to compare variance across trials to variance within a trial so you can determine whether the difference between two trials is real or not. As it turns out, the within trial variance can be quite small -- but more importantly, you can see the estimated CdA being updated every second, so you can often tell when the rider isn't holding the line on the turns. As far as variance across trials, we've detected changes such as someone opening the loading dock door, which affected either the air patterns or the air density or both. So the bottom line is that the within trial variance is small and when it's not you can usually see the cause; and when "baseline" runs look off you can also usually spot the cause. As for pegging a difference to a particular change, such as a water bottle placement, that does, of course, depend on experimental control.

maybe because it was a small??? I couldn't fit that thing on my big melon

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Eric Reid AeroFit | Instagram Portfolio
Aerodynamic Retul Bike Fitting

“You are experiencing the criminal coverup of a foreign backed fascist hostile takeover of a mafia shakedown of an authoritarian religious slow motion coup. Persuade people to vote for Democracy.”

The LG P09 worked well for me (triathlete - picture below) and for another camper who is cycling only this year and was set up more for TTs. I can't link her picture, but in the article on the main page, she's on the right side, second from the top.

Hello Ex-cyclist and All,

Ex-cyclist wrote: "The only time the Air Attack MIGHT be faster is if you are riding so head down you can't see."

I might be worth noting that there is a way to keep your head down and be comfortable and be able to see.

http://www.view-speed.com

Use View-Speed Cyclops glasses and see your speed increase about 1 mph.



Cheers,

Neal

+1 mph Faster

Kind of both.. Helmets are weird. And it kind of depends on how the TT and Tri position is set-up. If you are restricted to UCI regs you might actually end up a little higher in the front. It depends on how much power you can create 5cm behind the BB.

My position is pretty aggressive. Based on the ReTul I'm about 18.5 cm of drop. My eyeball and tape get it at 17.5. Jon is pretty aggressive too, but he tested best with the Bell Javelin and the Advantage 2. Brian has a stretched out position that Jim called a TT position, he was faster with the Giro Selector and Advantage 2.

So again it depends. The big take away was that the Advantage 2 is still a damn good helmet and was 2nd in almost everyone's test.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

It's awesome and great to learn from the testing that you guys did on the track! I've been a pure TT cyclist for the last 4 years and been on a few different TT bikes from a P2 to a P2SL to a BMC TM02. I recently bought a small Trek Speed Concept 7.2 and running a Hed Jet 4 in front and a Hed Jet Disc out back, with a Bell Javelin, Castelli short sleeved aero jersey and an Elite Chrono aero bottle on the seat tube. Pretty fast setup for the rolling hills here in the San Francisco peninsula.

How do you think a round bottle behind the seat neatly tucked away and pointing straight back would perform? Given that most of my rides are fairly short between 20-30 miles, having one bottle is all I need. I've tried all sorts of bottle placements with round and aero bottles, but still trying to decide which has the least drag penalty while having ease of access. If the bottle behind the seat is much better than my aero bottle on the seat tube, then I'd be inclined to switch over despite it being hard to reach. I know it's very personalized on position as I've read but if you have any general insights, I'd appreciate it!

Eric, what can you do? LG was nice enough to send us something no one commercially can get their hands on. At least they now know they'll sell at least 6 or 7 helmets.

On the flip side, it was also a big risk. Had it tested poorly or middle of the pack for the majority of people, like other helmets did, it could have hurt sales. They flipped a coin and came up winners.

Chris I'm pretty stretched out. My pre testing numbers were Hip Shoulder Elbow at 88 degrees and my elbow extension at 107 degrees. My post testing numbers are going to be even greater. My reach increased at least 4cm. There is zero room for me to move my Profile T3 aerobars further. They are as far forward as they can physically go. If you look at image 14 that's pre going out further, image 17 is final position. it's definitely not your typical triathlete elbows under the ears upper arms at close to 90.

I ride the narrow and stretched out is aero philosophy.

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

Our system has a variability of about 0.6% within a given set of laps. We call this "intra-run variability". We take, say 20 laps, remove the first 3 laps on each end, and measure the std deviation of the laps. Std Deviation/Avg Cda is about 0.6%.

Between runs, our system has 0.8% variability. We call this "inter-run variability". But this is under certain conditions: no air density transients, stable bike fit, and consistent riding. Air density transients, such as what happens if someone were to open a loading dock for prolonged periods of time, are deadly. Outdoor humid, warm air can easily change the air density by more than 2%. That's about 0.005 m^2.

A stable bike fit is one where you're not only comfortable enough not to shift around on the saddle, but that there is enough contact area on your saddle and elbow pads that you don't slip. The contact points must be positively stable -- translation: that it's impossible for you to move around. Jim's pretty good at making as sure as possible that his riders are stable on the bike. That said, occasionally we see examples of slip, shimmy and "one-cheek riding" around the turns. You have to stay vigilant as a test director. But sometimes people move around and you miss it.

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AndyF
bike geek

hmmm, never thought about it from that angle. great point.

although I didn't go to camp, based on all of your reports I'm pretty happy about my equipment choices.... Pearl Izumi sleeved suit with tight arms and a small Giro Selector that I cram my head into.

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Eric Reid AeroFit | Instagram Portfolio
Aerodynamic Retul Bike Fitting

“You are experiencing the criminal coverup of a foreign backed fascist hostile takeover of a mafia shakedown of an authoritarian religious slow motion coup. Persuade people to vote for Democracy.”

I want to try that Sm Selector. I have Nick's M/L and it's a tad big on my head. I can't seem to find a Sm anywhere. I did pick up a Sm Bell Javelin and I might convert that to a selector.

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

I have big-ish biceps and broad shoulders...you called me a body builder one time in a thread about IMTX a couple of years ago. What is the secret to me getting faster position wise?

You mentioned in one of your more recent posts about moving the cockpit more forward and out. Do you feel this is sustainable for an IM distance event?

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Brandon Marsh - Website | @BrandonMarshTX | RokaSports | 1stEndurance | ATC Bikeshop |

we can hook something up if you like

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Eric Reid AeroFit | Instagram Portfolio
Aerodynamic Retul Bike Fitting

“You are experiencing the criminal coverup of a foreign backed fascist hostile takeover of a mafia shakedown of an authoritarian religious slow motion coup. Persuade people to vote for Democracy.”

I haven't tried the P09, but a similar thing can be said with the Bell Javelin. The Jav is very narrow. I have a relatively narrow face and I could not wear a size medium with sunglasses.

Haha. You're so buff!

I think it's very sustainable. It's pretty comfy and easy to hold. With the bars angled up ~5 degrees it locks your elbows in.
EDIT: I could ride even more extended if I had extensions that were long enough.

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

:) So Brian, your greatest takeaway from the aero session was that ladies should wear much tighter tops...

Well I say we're about done on aero research... nothing more to be learned...

Thank you, fantastic research, I shall be informing all (decent looking) ladies of this vital fact.... and that logically the tighter you go the faster you go...

Cheers

You missed one thing. When in doubt. Ride a P09.

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http://www.frostyjunction.com/
https://twitter.com/FrostyJunction

  
You missed one thing. When in doubt. Ride a P09.[/quote]
Reaches for texter to label something P09.......

I achieved a stretched out fit using the 3T Wide Aero Clamps you recommended and then putting some pad holders on there with special holes to get them as forward as possible. So, wide enough elbows (which also allows you to really shrug those shoulders in), and as Brian said tilted up pads to "lock" it in. No muscular stress holding that position.

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Eric Reid AeroFit | Instagram Portfolio
Aerodynamic Retul Bike Fitting

“You are experiencing the criminal coverup of a foreign backed fascist hostile takeover of a mafia shakedown of an authoritarian religious slow motion coup. Persuade people to vote for Democracy.”

Do you have plans for building up a database of the results from all your testing? With so many athletes, positions, bikes etc. you have a potentially very powerful tool. Just like you found that the P-09 worked well for most athletes with some machine learning / data mining tools and enough data you could go into a test session knowing that athletes with a larger build on a P5 are most likely to get savings with a BTA bottle over an aero mount, but it might be the other way around on a Speed Concept.

I think that over the long term, if you collect good data, like bike, position, height, weight, race distance, etc. then you will have an amazing tool that will allow you to make more effective choices in the limited number of experiments you have but also people can make purchases that are more likely to benefit them even if they haven't been tested.

Malcolm

I'd second that. Not everyone lives near a wind tunnel. I'm sure there would be a market for people such as my self for advice based on specified permitters.

Andy, Jim and Robert,

Since last year, when we worked together, have you gained insight into how water affects the drag of suits? We all noticed drag decreased the longer I rode, attributing the decrease in drag to a rider stirring the air, drafting himself/herself. We've also noted how changes to the way fabric is finished alter the drag. Sweat saturation or dousing with water might alter the drag of fabric. Any data suggesting an increase or decrease related to fabric water content?

Hmmm. Perhaps it's because I have to worry about human subjects research but I would think there could be some potential privacy issues to resolve. You'd be on more solid ground talking about aggregate summaries and tendencies without getting into details that would identify a particular test subject (unless they're willing to out themselves).

Damon: I've never looked at that variable. Hmmm.

I'm a pretty big dude and I got a pretty low CdA in a pretty traditional position. When I stretched it it hurt my neck. The big thing we learned is you just never know what works until you test it. You are probably pretty dialed in and just need a few tweaks. If I was in your place I would try to figure out a way to get by the Velodrome and schedule some time if you have any events near there.

EDIT: Not surprisingly, after looking at a couple of the side images of you, there is nothing bad sticking out. The upper arm is basically at 90 degrees so you could probably extend a bit and go a touch higher with the hands like Brian suggested. What has been found is that arms perpendicular to the ground trend towards the slow side since you are putting two cylinders directly in line with the air. Angling them a bit tends to test on average faster. Since you have some upper body mass a sleeved suit would probably work on you as well.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

it is not possible to make specific recommendations to people based on other peoples' data. there are trends yes, but the over arching message of any aero testing is that individuality IS the message. and fyi, the overwhelming majority of tunnel customers fly.

Can we take it for granted that the smallest helmet you can fit into will be the fastest? Any data on helmet size from Aero Camp?

I'm curious because I accidentally ended up with a M/L Selector that was mislabeled S/M. It's also a little big on my head. However, the M/L with the deep tail is the only aero helmet I've ever tried on that sits flush against my shoulders/back, filling in the usual gap there. It also covers more of my face. I'm sure you take a small hit on frontal area with the larger size, but not much if your head position is low. I'm wondering if filling in that gap and shielding more of your face and shoulders helps your Cd more than it hurts your frontal area.

Wishful thinking on my part?

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CodyBeals.com | Instagram | TikTok
ASICS | Ventum | Martin's | HED | VARLO | Shimano | 4iiii | Keystone Communications

We didn't test different helmet size specifically. We did speculate a bit that might have have been why the P-09 tested well on me. The only one we had was a S-M 52-56 I normal wear a M-L. We have no real way of knowing without going back and testing both to make sure. A smaller helmet will have a lower frontal area which MAY test better.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

How does the Selector compare to the WingSpan? I currently have the wingspan but like the color/style of one selector model. Would it be an upgrade?

Also from your testing, could you say position 1st, Clothing and helmet 2/3rd? Or is it more Position 1st, clothing then wheel & helmet would be a wash with the hydration/bento box/etc. ? Which means they play those small role overall.

Thank you for your feedback.

Really, as we've said multiple times, it depends. In GENERAL the selector performed better than the wingspan. This may or may not be the case for you. It would probably not be a horrible bet though. Plus if you like the looks, then that a bonus.

We didn't test wheels, but an optimized helmet can likely save you the same as a good aero front wheel. Helmets and clothing play a huge roll, but for both fit is the key.

So Position is the HUGE number 1, I'd put wheels as number 2 since that is not really rider dependant, Helmet and Clothing is close to being tied for 3.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

Much appreciated, I guess time to get the selector and possibly sell the WingSpan (unless I'd need it for hot races).

The trend was the that Rudy helmets for the most part were solid mid pack performers, again YMMV.

After seeing the trends, when I see people racing with a Rudy aero helmet, my thought now is that for 80% of the people it's not the fastest helmet. But is the person I'm racing against in the 20% or the 80%?

Now the flip side of that is that the Selector wasn't always the fastest helmet either. You could wonder the same thing about the people you are racing who are wearing the Selector.

It's been said multiple times on here but is worth repeating. Unless you are going to do field testing or aero testing when you put on your aero helmet, you don't know if it's helping you a little or it's helping you a lot. Unfortunately my custom painted Rudy Wingspan is an aero brick on me. On you it could be The helmet or it could not.

The wingspan was talked about a bit more earlier in this thread iirc.

I think if you are planning on testing it's Position 1st, helmet 2nd then clothing or storage and then switch them. You need to carry fluid and food. Personally I' waiting on buying any aero clothes for LC racing until later this year. I strongly suspect there is a lot in development right now and waiting a few months may be the smarter option.

On the velodrome, since it's close to zero yaw, all wheels are going to do well. IMO there is enough data out there on wheels, that testing a wheel is a wasted run. I'd personally use that run to answer other questions.

EDIT: I see Heath was typing at the same time I was. Now you've got 2 different opinions on what to test. Not trying to confuse the issue, each person has different testing needs & priorities.

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

I've used the Selector for 3 seasons now and I've never had a race where I thought it was too hot. Is it hotter than a road helmet or the Specialized TT2? Yes, but I've never felt like it was a hinderance. YMMV

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

Id keep it and just wait for the P09 to be available to the masses

Not trying to pull traffic away from this thread, but for those that are interested, here is a link to a post with my personal data, thoughts, and trends. It's a bit too long to just copy and paste. Of course as said over and over again, it's all individual, but you can learn a lot and make some educated guess by seeing the results of others. A lot of the info in there I or other have discussed in this thread already but there is also some other fun info.

Aero Camp: The Data

Can you tell us what you do to verify proper power meter operation? It's clearly very critical for the test.

>>I ride the narrow and stretched out is aero philosophy

Narrow is aero, IMO. Thanks for the info. When is your next camp?

Congrats on the business venture.

Volleyball games played on the infield are problematic when trying to achieve a 0.8% inter-run variability, then? How does ~3% uncertainty effect results interpretation?

Here's some ambient condition data from the venue where you tested on a day where no volleyball games were being played and there were three people in the facility:

http://biketechreview.com/images/ambient_conditions_ADT_070208.png



best of luck going forward.

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Kraig Willett
http://www.biketechreview.com - check out our reduced report pricing
=================

Great question. Rich Sawiris at Wheelbuilder.com insures our Powertaps are calibrated properly; not sure there's anyone in the business who understands them better. We like using PT's for a few reasons, one of them being they don't drift. We've seen many a pm come through testing that we're clearly not calibrated properly, and it does have obvious effects. We had it happen at this camp, in fact. I absolutely agree with DCRainmaker's assertion that a majority of athletes are riding around with improperly calibrated pm's.

This has been enough of an issue that we're ready to insist everyone use only our Powertaps to insure consistent results. We've also considered offering a calibration service, but time is an issue for us.

Beyond that, the pm being used is zero'd before every run. We definitely can see when a pm drifts and, trust me, some very obviously drift during a test.

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Jim Manton / ERO Sports

We check in real-time at all times, and adjust before every run if necessary. The only time we see those changes is when doors are left open. We've done thousands of laps over hundreds of hours and never see changes that dramatic unless a door is left open, and it's pretty obvious when it happens.

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Jim Manton / ERO Sports

Excellent plot and it nicely illustrates the issue! The plot shows a couple of things: first, that as long as you record the data you can adjust for air density. Second, that although there are often changes in air density over the course of testing, there's usually a secular trend which makes accounting for it easier. Third, you can see transient spikes (like, at ~12:40pm, ~1:05pm, and a smaller spike at ~1:35pm). The good things are that the spikes are transient and obvious. Bottom line, it's not like air density varies randomly -- air density appears to vary in predictable ways and when it doesn't (like, the spikes) you can spot it and either correct for it or handle it in another way. This is a great graph.

Thank you!

You raise a good point that measuring air density plays an important role in making sure the CdA measurements are solid.

We do measure it continuously, and incorporate it into the calculation. But what we don't like is when storm fronts come in in the middle of a run. It's the quick transients that hurt. We've also tested *a lot* at the VELO Sports Center. Maybe 20,000 laps. And we see our Stig runs, that keep coming in at the same CdA +/- 0.8% when we're careful.

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AndyF
bike geek

I seem to recall dcrainmaker took a pretty big hit with a bta bottle in testing the profile mount(though it seemed like it also could have just been the profile mount). I wish there was some way of knowing whether or not a bta is a good call. The 5 watt hit you saw is higher than just a regular fram bottle, is it not? There has also been speculation that a bta is better at yaw, so doesn't this demonstrate partially a shortcoming of the testing?

Was there any talk of trying to create a system that created a way to test higher yaw on the velodrome?

I'm sorry, sir. What is this "storm front" thing you speak of? When I purchased my SoCal home I was assured by the realtor that we don't experience such phenomena here. :-)

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Jim Manton / ERO Sports

In the A2 testing we went to this summer, a round bottle on the seat tube was a 9w hit. I know others where the BTA was a watt saver. Again, it varies. If you look at pic 4, every single person said no way is that going to test fast (BTA sticking up in the wind). Yet it tested fast and faster than the Xlab torpedo that tucked so you could hardly see it.

As the yaw goes out you normally see a reduction., we saw that quite often at A2. If it was better at baseline 19/20 runs it was better at yaw. The velodrome isn't 0 yaw. Jim and Andy can better tell you what yaw it averages out to be, maybe 2-3 is my guess.

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

DA is light green in the second panel of the plot and the variation doesn't look to be monotonic. Measuring DA is nice, but measuring q is probably better?

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Kraig Willett
http://www.biketechreview.com - check out our reduced report pricing
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I agree that field testing can be done well.

I guess I look at it from more of a customer perspective. During this test, one individual did a repeat run that was approximately a 2-3% delta. How does that effect interpretation of their results?

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Kraig Willett
http://www.biketechreview.com - check out our reduced report pricing
=================

Yeah, monotonicity would be nice but what's more important is that the time scale of the change is slow enough that you can pick out a secular trend (and then adjust for it). I think what's being continuously monitored is temp, pressure, and humidity so rho is calculated.

Well, I'm not Andy or Jim or Brian or Heath but when I see large and unexpected deltas in any of the work I do (and, of course, most of my work doesn't have anything to do with aero measurement) I have to look around to see if it can be explained. That's just good analytical practice.

2-3% is a significant change, for sure.

Your point is well taken -- it would be hard to find any subtle deltas in that kind of noise. We are still sifting through the detailed ANT+ log files to find evidence of a power meter that wasn't properly zeroed. We can backtrack and redo the calcs, if that's the case.

I promise to share the findings.

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AndyF
bike geek

I went back and looked at the run list and based on the notes we have it wasn't a true back to baseline as there was a different helmet involved that what the baseline was. Unless the notes are wrong, I don't think there was really much going on there that would have raised any eyebrows.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

Heath-
If you are referring to my two differing baselines, they were done with same position (extensions up, dropped 2cm) and same helmet (Rudy Wingspan).

If not, disregard the above.

ETA: Just went back and checked the testing report, "Setup #7" is incorrectly labelled as testing #2 + Wing57, it actually was a complete return to #2. Would have liked to test the Wing57, but it was not down at the track yet. Notes were likely taken with Rudy, Wing, or poor hand writing. Shot Brian an email asking to have that corrected for the sake of other people looking at the data a couple days back..

A CxA reduction of ~14% is extraordinary. Here are two pics that reduced CxA by roughly half the magnitude you are reporting:



http://www.biketechreview.com/...riding_arms_back.png

Do you have images that compare the CxA=0.264 and the CxA= 0.227 runs?

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Kraig Willett
http://www.biketechreview.com - check out our reduced report pricing
=================

Heath is pictured in 16 and 20 and the captions talk about some of his changes. Sounds like clothes and helmet were a big part of things http://www.slowtwitch.com/..._Aero_Camp_4145.html

Before reading further - please keep in mind that I'm really not trying to be a pain in the ass here; but rather, I'm trying to help folks put these results that have been posted into some sort of context.

If it's not too much bother, please talk more about what you actually check in real time _prior_ to a run, and what are the criteria/thresholds that are used to determine if an adjustment is necessary.

How does the facility exit egress/ingress rate during a volleyball match (images show a volleyball tournament occuring during testing) affect transient wind patterns?

Of the folks that tested, how many did repeat runs of the same configuration? We've seen one individual do a repeat with a reported (as of 1/25/14) 2-3% change in CxA. I'd be curious to hear more about the practical/typical/average-non-stig-person repeatability of the methodology implemented at this venue.

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Kraig Willett
http://www.biketechreview.com - check out our reduced report pricing
=================

thanks for the heads up on the images. his position and equipment in 16 suggests to me that a 14% improvement is indeed extraordinary.

fwiw, a std road helmet to a full-on aero helmet is about a 3% delta at beta=0.

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Kraig Willett
http://www.biketechreview.com - check out our reduced report pricing
=================

Do you have 650c wheels with powertaps?

Can you expand upon this educated guess please? Does it refer only to how the Aeon tested, or more about position et al?

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_____________________________________
What are you people, on dope?

—Mr. Hand

You of all people should know better than to trust the "eye-ball" wind tunnel. And I'm sure you're not suggesting that your eye is better than what they are doing up the road from you at the Velosports Center.

At any rate, my baseline run was .2643. That is what is pictured in number 16. My next change was dropping the armrests down 1cm. that got me to .2507. I then took off the rear bottle which barely moved the needle but did slightly down to .2494. The helmet, as your extensive experience showed you was not a huge CdA dropper, but it did drop it to .2447. The last change was to test in the PI skin suit, that dropped me down to .2267

This seems to jive pretty well with what others have found:

http://forum.slowtwitch.com/cgi-bin/gforum.cgi?post=4165683#4165683


And based on manufacturers claims from companies like Castelli and Pearl, while eye opening, the savings from the suit doesn't seem too far out of line. FWIW, the Kiwami suit is a probably not as tight as it should be (I ordered up a size due to body length which was a mistake) and it exposes a lot more skin than a normal top.

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Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

I don't have a dog in this fight...I rarely do wind tunnel work with athletes these days. Field testing can be done well, but it is tricky. And, yeah, my eyeball is a good independent line of inquiry, and when things don't jive with it, it piques my curiosity...and then I test again, and again, and again, and...y'know, to make sure what I'm measuring is indeed there and not just noise.


how many repeats of this configuration did you do?


that is an extraordinary improvement for a 1cm change in drop. Are there any other things that might explain this large delta?


a good head position is pretty robust to aero helmet choice. a 2% delta seems high for an aero helmet to aero helmet swap even with a non optimal head position.


that is an extraordinary difference. A CxA reduction of ~0.02 is roughly equivalent to going from a road jersey that is a couple sizes too big to a skin-tight one in my experience.

Again, I don't have a dog in this fight, but this thread reminds me of the quote: "No one believes the results of a theoretical analysis except the analyst. Everyone believes the result of an experiment except the experimentalist."

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Kraig Willett
http://www.biketechreview.com - check out our reduced report pricing
=================

I think a drop of more than 10% is possible, especially with amateur triathletes that did not have much prior testing done and you optimize both position and equipment.
I liked the graph you posted, but as long as air density is accounted for in the calculation I do not see a problem. Also I have seen spikes in temperature and increased humidity like that when somebody picks up the device to take a reading. That would be aVERY lokalized effect and would not effect the measurement.
I think I send you tunnel data before trying to attach a probe to a bike to measure dynamic pressure and found way to much rider interaction in every acceptable position. so I disagree that measuring q would be the better idea. I think field testing works and has been showen to give usable results. The biggest source of error is the rider.

I asked about this but wasn't responded to...

How does an aero bottle on the down or seat tube perform on a Speed Concept in general? How about just having a single behind-the-saddle bottle setup vs a frame-mounted bottle?

Any generalized insights?

Thanks.

I alluded to this earlier. It depends upon the size of the frame. What size frame do you have?

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

I agree. Are you suggesting Heath is an amateur triathlete that hasn't done his homework? To me, his position/equipment during his first run looks pretty good - certainly not like the folks I've seen get 10%+ improvements in CxA.


I think the real reason I posted the graph I did (data taken during an ADT test session quite some time ago when no volleyball games were being played) was primarily to illustrate non-monotonicity of DA. One of the individuals who tested on the day(s) of the aero camp that is the subject of this thread mentioned that they thought there was a linear drift between runs...maybe there was, and maybe there wasn't - without measurement of the things that matter, it's difficult to say. The test director on the day is the guy who will be able to shed some light on how these things are measured and dealt with systematically/automatically.


I haven't seen your data. Please share it in this thread. I'm sure there are folks smarter than I reading who might be able to provide some insight. If you are basing your perspective on data acquired in a wind tunnel where blockage might be a factor, that is something to consider. I agree that field testing can work, as long as one understands the limitations of their tool/methodology. That could be a serious piece of work to undertake for a given individual who shows up on field-test day.


I'd agree as long as everything else that matters is measured and accounted for. In a wind tunnel, where the force and q measurements are calibrated and known day to day or rider to rider, yeah, for sure, the rider and the clothing they choose to wear on the day are a big source of error. In a venue where the force (i.e, power meter of unknown calibration and ability to deal with reverse torque) and ambient conditions (e.g. air density, wind pattern changes due to associated behaviors during volleyball games in the infield etc...) are not known, well, then, maybe I'm not as sure as you seem to be....and as Bjorn alluded to earlier, without the means to verify or record how rider's behave _during_ a run, well, things could very well be a bit of a dog's breakfast.

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Kraig Willett
http://www.biketechreview.com - check out our reduced report pricing
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