fair enough...

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Swimming Workout of the Day:

Favourite Swim Sets:

2020 National Masters Champion - M50-54 - 50m Butterfly

I'm leery of Orbea's new bike tbh. I really like the direction they went with certain design decisions (e.g. standard cockpit, direct mount brakes, boss behind seat tube for storage, vertical dropouts) and it looks like a very easy bike to travel with but until I see aero data there's no way it's replacing my Speed Concept.

Can you point me to where Cervelo or others actually show how their superior aero frames truly give an outdoor advantage? I've never seen it, but if you have it and it's legit, I'm willing to believe it.

I'm sure they DO test them outdoors, but again, I've yet to see convincing proof that shows their wind tunnel data is legit outdoors.

I'm not aware that they have published it.
You could refer to some of Tom A's field testing on various cervelo frames. Or perhaps pick the brains of some of the people who have been to EROSport.

But unless you think Cervelo manages to find shapes that somehow work in a wind tunnel but not outside, despite the fact that in general these things work the same, I don't know why you are so suspect. Again, see figure 2 in the link.

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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

I am absolutely suspect!

Seriously, if you had good, reliable data showing that your wind tunnel effects are measurable and reproducible outdoors, why would you choose to hide it?

This type of surrogate-testing as-proxy is a well-known method in the biological sciences of trying to indirectly 'prove' something even if really doesn't work. For example, your drug might not cure diabetes humans, but you could get a lot of excitement from investors and even science publications by showing that it cures diabetes in mice or other surrogates. It's interesting stuff, no doubt, but still a far cry from saying it works in the circumstance that you are trying to prove, which is humans (or outdoors, in bikes case.)

http://cms.trekbikes.com/...adone_whitepaper.pdf

starts with CFD-tunnel correlations, gets into velodrome testing on pages 15-16, and finishes up with lots of multi-rider field testing on pages 34-38

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Carl Matson

He thinks bike companies are like Volkswagen.

Aerostick!

This is the part of the thread where I humbly illustrate that this thread has:

1. Reverted once again to the endless, circular argument about the aerodynamic merits of bikes.

2. Potentially illustrated that selling the same thing the same way probably doesn't sell anything that wasn't already going to be bought.

Here's what I mean, and some of you already know this:

The sport has grown in participation. Lots of new triathletes. Very few are contributors or readers on the Slowtwitch.com forum. It's a new demographic. The industry is still selling to the old demographic. It appears afraid to even try to sell to the new demographic with a fresh approach.

Examples in other industries:

Coca-Cola raised brand awareness with their beverage by putting peoples' names on the cans.

Apple introduced computers with metal bodies, different looking and functioning retail outlets and cross-device connectivity.

Casio made an inexpensive digital watch focused not on time keeping accuracy or fashion appearance but on durability, the G-Shock.

Ford popularized a vehicle category started by International Harvester called the "Sport Utility", something people never realized they wanted.

Dan Empfield marketed a new bike category by changing the orientation of the riders' pelvis to the bottom bracket and other geometric changes.

And here's my point: There is untaped opportunity here.

What is the average bike speed of most people doing Ironman? I'm not talking about the top 15%. What does that customer really find useful?

And finally, why isn't the industry marketing to that segment?

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Tom Demerly
The Tri Shop.com

This is the part of the thread where I humbly illustrate that you have an axe to grind.

Good points, I think.

Most of our tri fit clients aren't regulars on ST, and a surprising number don't even know about this site. ERO, along with a few other companies (Louis Garneau, PowerTap, Profile Design), are going to partake in a project over the next few weeks where we take an "average" triathlete and see just how "ERO" we can make her. She's a mom, never much of an athlete, she'll never likely sniff a podium, but she very much represents the majority of newer triathletes. She recently borrowed a power meter, and noted she was using more watts to go slower than her friends. I thought it was pretty cool that she noticed, and it re-enforced in me that position, aerodynamics, equipment choice, proper training, etc. are important for everyone, not just the pointy end of the sword. Virtually everyone, no matter how "fast" they may be, cares about getting the most out of themselves. I do see the industry going after them, but perhaps there's a better way.

As for credibility of aero test claims? Well, I've posted on that many times now; testing one frame vs another is silly. Heath is right, find your position, and then get the bike that allows you attain it. Frames are far down the list of importance if you're looking strictly at aero drag. Weight - who cares? We're beyond weight at this point.

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Jim Manton / ERO Sports

And of critical note in that document - the only time they compare other bike manufacturer designs to their bike is in the wind tunnel and velodrome.

ALL of the outdoor testing in that document is not against other bikes - it's just additional testing on their own frame with different yaw angles, etc. They specifically AVOID showing any data of testing various other bike frames against theirs outdoors. Even if the data was imperfect (due to varying wind, rider consistency, etc.), I still would want to see how big (more likely how small/irrelevant) the measurable difference are outdoors.

I definitely am ok with both the wind tunnel and velodrome data in terms of how they test between frames/companies, but I'm definitely still not sold on how measurable these effects are between frames in outdoor settings.

This isn't a trivial issue - we triathletes race bikes exclusively outdoors and not in a velodrome, so if we're going to buy into how effective their highly researched frames are, they should have data that reflects it in the outdoor conditions. If the outdoor variables are big enough to render all their engineering to the level of background noise in terms of speed gains, the conclusion drawn should be 'insignificant' between different frames in real-world OUTDOOR practice.

It may not be the only, but it was the first. (BTW, you can find a cleaner copy here: https://www.academia.edu/...mech_1998_14_276-291)

The irony is that the stimulus for the study was the frustration that Jim had with "aero deniers" like lightheir. Now here we are almost 20 y later, and they still exist!

Apparently you've never heard the saying, "absence of evidence is not evidence of absence?"

Regardless, at least in the right hands field testing can be quite precise:

http://www.trainingandracingwithapowermeter.com/...aerodynamicists.html

and is sufficient to detect the difference between, e.g., aero frames:

http://www.trainingandracingwithapowermeter.com/...-p2t-or-javelin.html

http://www.trainingandracingwithapowermeter.com/...-p3c-or-cervelo.html

Yeah, but would you talk to his wife?

Variability estimates, did you say?

http://www.tririg.com/...omega_whitepaper.pdf

(BTW, think if I posted this to ResearchGate.net as a work-in-progress everyone would assume it is a peer-reviewed paper? Based on recent events, I bet most people would.)

without letting this go too much further into rabbit-hole/hijack territory...


not because there's something to hide, but because it wasn't the purpose of the testing. the point was to establish relevance of aero data even in drafting situations, period...not to establish whether or not one frame performed better than another in a given drafting situation. seemed like a prudent thing to investigate, since there's a chunk of the road market in particular which gets hung up on "but it all goes away in the real world when you're drafting"...conveniently forgetting that in the real world you're still moving through air.

<steps back into black helicopter>

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Carl Matson

Anything with slight bias I don't give much credibility to but I don't think its that far off either. It would be nice if there was a all powerful independent wind tunnel tester that did yearly reviews on the major products and published it. I realize that's probably not going to happen as the financial requirement even with companies cooperation has to be much more than any return would provide.

For example, who's to say when testing the cable excess on the derailleurs and brakes is longer? The type of handlebars used is important, bar tape, etc. There are all kinds of ways to slightly fudge data.

Personally, I like to see how the equipment stands as a single item (i.e. the frame) and not a full setup. For tri bikes with integrated setups it can't be done but with road bikes most of us chuck the handlebars and wheels after getting a bike so testing products stock means nothing for some of us.

It actually very might go away in the real world. If the external variable forces are enough to render the small gains of the aero frame immeasurable, those vaunted wind tunnel gains are in fact 'gone' on race day. It is critically important to interpret the magnitude of the speed gain relative to the expected variability of 'real world situations.'

This would be analogous to having a blood pressure drug, that in the lab, with humans, absolutely lowers blood pressure by 1mm HG in the lab, but has no measurable effect on BP out of the lab, due to the variability of human physiology/BP which makes a 1mmHG difference clinically useless. There is no clinician that would say that this was an effective hypertension drug worth prescribing to reduce real clinical hypertension, despite the rock-solid data that it really does lower blood pressure (by a measly 1 mmHG.)

Logic isn't your strong suit, now is it?


1 mmHg is 1 mmHg, regardless of the variability of the measurements.

The testing you do in the javelin/cervelo links is the kind of data that bike manufacturers SHOULD be providing. I would love to see more frames tested in this manner, outside of the wind tunnel.

Given your extensive expertise in this area, and your research that such OUTDOOR testing should not be difficult in practice and also should yield highly precise results (both premises I absolutely agree with), then what do you think the reason is why bike manufacturers never show A/B comparison OUTDOOR data versus other bikes, if their frame is in fact, superior?

This situation would be akin to multiple hypertension medication manufacturer saying they have a great drug with great effects, but not one of them providing a single clinical trial outside of highly controlled lab conditions to prove it. If the medication (or frame) is really so effective - why can't they show it works in the real world or in real conditions if it's not so hard to test it?

Anyone sell any bikes yet?

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Tom Demerly
The Tri Shop.com

That was my point, which he of course ignored.

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

I've no idea where you are going with this. I don't sell bikes so don't know the mindset that you're alluding to, nor the current bike that has the elusive 'mojo'.

I will, add, Dr. Coggan, it's not encouraging when you respond to a very reasonable claim I've made with a 'ad-hominem' attack about my logic or lack of, which completely avoids addressing the situations I've presented.

You're not hurting my feelings, as I have enough academic credentials to feel good about my logic, but it certainly undercuts the message you are trying to get across, nor does it refute what I have said.

And 1mmHg is 1mmHG is true, but I still stand by my point that such a small magnitude difference needs to be considered before changing practices to incorporate this drug before other more effective means. In fact, you should probably make the argument with this data that you should completely ignore this drug, and spend your time on all the other more highly effective means of treating hypertension - an analagous approach would be a coach advising someone to ignore the gains of aero vs nonaero bike frames and focus on rider position and aerobars instead.