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Re: The Aero Bike Shootout: New vs. Old; Rim vs. Disc; Direct to Consumer vs. Retailer; Beam vs. Double Diamond (*an update*) [Slowman] [ In reply to ]
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Hmmm.
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Re: The Aero Bike Shootout: New vs. Old; Rim vs. Disc; Direct to Consumer vs. Retailer; Beam vs. Double Diamond (*an update*) [Slowman] [ In reply to ]
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As I mentioned in another K.A.Y. post

I would like to know the motive behind the man............other than vanity
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Re: The Aero Bike Shootout: New vs. Old; Rim vs. Disc; Direct to Consumer vs. Retailer; Beam vs. Double Diamond (*an update*) [Slowman] [ In reply to ]
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Slowman wrote:
it is, nevertherless, the policy. best warm yourself up to it.

kiley and i have traded a number of PMs. the test is not going to be published here unless i'm convinced that the test is done correctly. there is plenty of time and opportunity to convince me of that, and what will convince me is not onerous. if the test is husbanded by somebody (or somebodys) who know what they're doing, and the protocol and process is sound, then i have no quarrel hosting its publication.


Dan.. what I hope is a fair question. Are you going to apply that policy universally? We have seen plenty on here that doesn't meet this new standard.

EDIT.. ignore me, this has been covered. I only got a few posts into the thread and my astonishment overtook my patience.

Would love to get your thoughts on the P5x white paper, though.
Last edited by: knighty76: Apr 12, 17 6:09
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Re: The Aero Bike Shootout: New vs. Old; Rim vs. Disc; Direct to Consumer vs. Retailer; Beam vs. Double Diamond (*an update*) [Grill] [ In reply to ]
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Grill wrote:
Is this a rider on bike test?
if so, it's useless for product comparison purposes.

Trent Nix
Owned and operated Tri Shop
F.I.S.T. Advanced Certified Fitter | Retul Master Certified Fitter (back when those were things)
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Re: The Aero Bike Shootout: New vs. Old; Rim vs. Disc; Direct to Consumer vs. Retailer; Beam vs. Double Diamond (*an update*) [knighty76] [ In reply to ]
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"Dan.. what I hope is a fair question. Are you going to apply that policy universally?"

no. i don't have to ask trek or cervelo to do the test correctly, and unbiased. since rchung has chimed in (with a comment the meaning of which i can't decipher), i would not question him or ask him to establish his bona fides if he proposed to publish on a test of his, because he hasn't made outrageous comments about some of the products he purports to test, and because he has in the past established his bona fides.

we're in unprecedented territory here. we're in the era of trump. i don't know what era we're in. but after having been at this business a good long while my instinct tells me to look hard over the shoulder of this before i let it be published in a place i control and am responsible for.

and, look, i'm happy also just saying fuck-all, i don't have the time to scrutinize this test. circle-jerk it on twitter amongst yourselves. i've got better things to do. nevertheless, i'm willing to accommodate this test as well as i know how. but those are my non-negotiable terms.

Dan Empfield
aka Slowman
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Re: The Aero Bike Shootout: New vs. Old; Rim vs. Disc; Direct to Consumer vs. Retailer; Beam vs. Double Diamond (*an update*) [trentnix] [ In reply to ]
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trentnix wrote:
Grill wrote:
Is this a rider on bike test?
if so, it's useless for product comparison purposes.

Perhaps, but some bikes test very well with no rider (Ventum) and others do better with a rider (P5). Personally I don't give a monkey's how fast my bike is when I'm not on it.
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Re: The Aero Bike Shootout: New vs. Old; Rim vs. Disc; Direct to Consumer vs. Retailer; Beam vs. Double Diamond (*an update*) [Grill] [ In reply to ]
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Grill wrote:
trentnix wrote:
Grill wrote:
Is this a rider on bike test?
if so, it's useless for product comparison purposes.

Perhaps, but some bikes test very well with no rider (Ventum) and others do better with a rider (P5). Personally I don't give a monkey's how fast my bike is when I'm not on it.
the rider destroys the integrity of the test because the rider can't adequately control their position.

I hear you and concede your point, but it doesn't change the fact that tunnel data with a rider on the bike makes bike comparisons effectively useless. It's why Cervelo uses foam DZ.

Trent Nix
Owned and operated Tri Shop
F.I.S.T. Advanced Certified Fitter | Retul Master Certified Fitter (back when those were things)
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Re: The Aero Bike Shootout: New vs. Old; Rim vs. Disc; Direct to Consumer vs. Retailer; Beam vs. Double Diamond (*an update*) [blaxxuede] [ In reply to ]
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"That being said I was under the assumption the data was only available to contributors?"

in which case we don't have any disagreement here. if data is only available to contributors then the data won't be published here and i don't really have any say-so (and don't deserve any say-so). i'm simply saying in advance what my terms are for publication here.

Dan Empfield
aka Slowman
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Re: The Aero Bike Shootout: New vs. Old; Rim vs. Disc; Direct to Consumer vs. Retailer; Beam vs. Double Diamond (*an update*) [Slowman] [ In reply to ]
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thanks for taking the time to clarify some.

My Blog - http://leegoocrap.blogspot.com
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Re: The Aero Bike Shootout: New vs. Old; Rim vs. Disc; Direct to Consumer vs. Retailer; Beam vs. Double Diamond (*an update*) [trentnix] [ In reply to ]
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Quote:
the rider destroys the integrity of the test because the rider can't adequately control their position.


It's harder for a rider to control their position. But we've seen riders time after time get within .002 of their CdA in the tunnel run after run in the same position.

Brian Stover USAT LII
Accelerate3 Coaching
Insta

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Re: The Aero Bike Shootout: New vs. Old; Rim vs. Disc; Direct to Consumer vs. Retailer; Beam vs. Double Diamond (*an update*) [Slowman] [ In reply to ]
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the personalities behind this test have chosen sides.

Are you accusing Heath or I or A2/Geoff of having a side in this? If that is the case you need to back the F off that soap box. Right now.

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i'd like the person with requisite wind tunnel experience to describe to me methods and protocol.

I told you to email me and I'd explain everything.

What it sounds like is you're questioning our knowledge, experience and abilities. If you use the search function you'll see we've done product testing/design for several companies and had direct impact on multiple world championships on the pro level with our testing

Brian Stover USAT LII
Accelerate3 Coaching
Insta

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Re: The Aero Bike Shootout: New vs. Old; Rim vs. Disc; Direct to Consumer vs. Retailer; Beam vs. Double Diamond (*an update*) [kileyay] [ In reply to ]
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I may come for a few hours as an independent observer and snag pics
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Re: The Aero Bike Shootout: New vs. Old; Rim vs. Disc; Direct to Consumer vs. Retailer; Beam vs. Double Diamond (*an update*) [trentnix] [ In reply to ]
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trentnix wrote:
Grill wrote:
trentnix wrote:
Grill wrote:
Is this a rider on bike test?
if so, it's useless for product comparison purposes.


Perhaps, but some bikes test very well with no rider (Ventum) and others do better with a rider (P5). Personally I don't give a monkey's how fast my bike is when I'm not on it.
the rider destroys the integrity of the test because the rider can't adequately control their position.

I hear you and concede your point, but it doesn't change the fact that tunnel data with a rider on the bike makes bike comparisons effectively useless. It's why Cervelo uses foam DZ.

So use a mannequin or borrow DZ. Lots of us know our position well enough to be able to hold it as long as the geos are identical. I'd rather have rider-on with some margin of error, than just bike only.

The rider is the most important part of the system when it comes to drag, so not taking them into account already makes the test useless.
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Re: The Aero Bike Shootout: New vs. Old; Rim vs. Disc; Direct to Consumer vs. Retailer; Beam vs. Double Diamond (*an update*) [desert dude] [ In reply to ]
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" If you use the search function you'll see we've done product testing/design for several companies and had direct impact on multiple world championships on the pro level with our testing"

in which case what i'm asking for will be an easy hurdle.

just, to be clear, running a wind tunnel test is an art distinct from (say) being a fluid dynamics expert who doesn't have wind tunnel experience. there are also particulars to testing one bike v another that i am familiar with, and i want to make sure you know what you're doing in that kind of test.

and with that, i'm done here. have to go shoe some horses. we can argue about this. or you guys can just give me what i'm asking for.

Dan Empfield
aka Slowman
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Re: The Aero Bike Shootout: New vs. Old; Rim vs. Disc; Direct to Consumer vs. Retailer; Beam vs. Double Diamond (*an update*) [desert dude] [ In reply to ]
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desert dude wrote:
Quote:
the rider destroys the integrity of the test because the rider can't adequately control their position.



It's harder for a rider to control their position. But we've seen riders time after time get within .002 of their CdA in the tunnel run after run in the same position.
I don't doubt that, but is that the norm or the outlier? Were the rider to dismount, change bikes (assuming the same geometry), and then ride could they achieve similar results? And then what if the ergonomics of the armpads are different?

I'm not trying to be obstinate, I just want to people to recognize good wind tunnel testing is exceptionally difficult, even when done by smart, well-intentioned people. And that's why most wind tunnel testing isn't very useful or helpful in making purchasing decisions. It's also why people are generally hesitant to provide the results of their testing.

You can learn a lot from testing in the wind tunnel, but you can't really figure out which bike is best for a consumer. But that's exactly what people think tunnel data is telling them.

Trent Nix
Owned and operated Tri Shop
F.I.S.T. Advanced Certified Fitter | Retul Master Certified Fitter (back when those were things)
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Re: The Aero Bike Shootout: New vs. Old; Rim vs. Disc; Direct to Consumer vs. Retailer; Beam vs. Double Diamond (*an update*) [desert dude] [ In reply to ]
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Sounds like Dan is just being biased bc of Kiley which is fine but he did a poor job of stating that. He makes it sound like he's questioning everybody involved when really it's probably only Kiley he really has concerns about.
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Re: The Aero Bike Shootout: New vs. Old; Rim vs. Disc; Direct to Consumer vs. Retailer; Beam vs. Double Diamond (*an update*) [trentnix] [ In reply to ]
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trentnix wrote:
You can learn a lot from testing in the wind tunnel, but you can't really figure out which bike is best for a consumer. But that's exactly what people think tunnel data is telling them.

That's not really true. YOU can't figure out which bike is best for your customer, but that customer can use information given by you regarding aerodynamic testing and use the aggregate knowledge to decide. As you well know, MOST customers don't read ST. In fact, 95% of the triathlon consumer world has very little idea of what ST is other than "oh yea, I don't go there, they're all douchebags" (seriously).

Plus, Kiley's position is very solid, and he practices it a lot. Whether he uses himself or some sort of mannequin the rider-on data will be as good as it is possible to be.
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Re: The Aero Bike Shootout: New vs. Old; Rim vs. Disc; Direct to Consumer vs. Retailer; Beam vs. Double Diamond (*an update*) [Grill] [ In reply to ]
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Grill wrote:
So use a mannequin or borrow DZ. Lots of us know our position well enough to be able to hold it as long as the geos are identical. I'd rather have rider-on with some margin of error, than just bike only.

The rider is the most important part of the system when it comes to drag, so not taking them into account already makes the test useless.
Were it only that easy (and that's not easy).

Even if you did have DZ, then you have to fairly set up the tests, meaning you find the optimal size for each bike given it's relative geometry (no testing 54 vs 54, for example, but armpad stack vs armpad stack). And even then, the aerodynamic profile of many bikes is different from size to size.

Take the Felt IA, for example. The larger the bike, the faster it is relative to the field. I believe I've seen Dave Koesel (he can't correct me if I'm incorrect) argue that the bigger size is faster than the smaller size, because the bigger airfoil of the Felt IA reduces drag at some yaws (even though surface area is larger). If that's indeed the case, then one bike might test better for a rider with a 600 armpad stack than might test for a rider with a 640 armpad stack.

Trent Nix
Owned and operated Tri Shop
F.I.S.T. Advanced Certified Fitter | Retul Master Certified Fitter (back when those were things)
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Re: The Aero Bike Shootout: New vs. Old; Rim vs. Disc; Direct to Consumer vs. Retailer; Beam vs. Double Diamond (*an update*) [James Haycraft] [ In reply to ]
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James Haycraft wrote:
trentnix wrote:
You can learn a lot from testing in the wind tunnel, but you can't really figure out which bike is best for a consumer. But that's exactly what people think tunnel data is telling them.


That's not really true. YOU can't figure out which bike is best for your customer, but that customer can use information given by you regarding aerodynamic testing and use the aggregate knowledge to decide. As you well know, MOST customers don't read ST. In fact, 95% of the triathlon consumer world has very little idea of what ST is other than "oh yea, I don't go there, they're all douchebags" (seriously).

Plus, Kiley's position is very solid, and he practices it a lot. Whether he uses himself or some sort of mannequin the rider-on data will be as good as it is possible to be.
But then that begs the question that testing with a rider is superior to testing without. I think I'm arguing that testing without a rider provides better discernment between bikes (assuming they are set up appropriately, of course).

The rider certainly makes up the bulk of the drag, but if you want to test apples to apples and you don't have options like FDZ, I think you might get better and more meaningful comparison data by testing just the bikes on their own.

Trent Nix
Owned and operated Tri Shop
F.I.S.T. Advanced Certified Fitter | Retul Master Certified Fitter (back when those were things)
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Re: The Aero Bike Shootout: New vs. Old; Rim vs. Disc; Direct to Consumer vs. Retailer; Beam vs. Double Diamond (*an update*) [trentnix] [ In reply to ]
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trentnix wrote:
Grill wrote:
So use a mannequin or borrow DZ. Lots of us know our position well enough to be able to hold it as long as the geos are identical. I'd rather have rider-on with some margin of error, than just bike only.

The rider is the most important part of the system when it comes to drag, so not taking them into account already makes the test useless.
Were it only that easy (and that's not easy).

Even if you did have DZ, then you have to fairly set up the tests, meaning you find the optimal size for each bike given it's relative geometry (no testing 54 vs 54, for example, but armpad stack vs armpad stack). And even then, the aerodynamic profile of many bikes is different from size to size.

Take the Felt IA, for example. The larger the bike, the faster it is relative to the field. I believe I've seen Dave Koesel (he can't correct me if I'm incorrect) argue that the bigger size is faster than the smaller size, because the bigger airfoil of the Felt IA reduces drag at some yaws (even though surface area is larger). If that's indeed the case, then one bike might test better for a rider with a 600 armpad stack than might test for a rider with a 640 armpad stack.

But at that point, what's the point at all?? If you can't normalize it to a reasonable degree based on: these are the bikes that fit me, I will test them how they fit me, and how I would use them for a 70.3....then what are any of us doing here at all? You can throw out essentially every single white paper and every aero test that anyone has done because it's not ME on MY bike.

I think you do as much as you can, and you run with it. You control what you can to a reasonable degree based on cost and time constraints as well as equipment availability. And then you have a pretty darn good test.
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Re: The Aero Bike Shootout: New vs. Old; Rim vs. Disc; Direct to Consumer vs. Retailer; Beam vs. Double Diamond (*an update*) [trentnix] [ In reply to ]
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trentnix wrote:
Grill wrote:
So use a mannequin or borrow DZ. Lots of us know our position well enough to be able to hold it as long as the geos are identical. I'd rather have rider-on with some margin of error, than just bike only.

The rider is the most important part of the system when it comes to drag, so not taking them into account already makes the test useless.
Were it only that easy (and that's not easy).

Even if you did have DZ, then you have to fairly set up the tests, meaning you find the optimal size for each bike given it's relative geometry (no testing 54 vs 54, for example, but armpad stack vs armpad stack). And even then, the aerodynamic profile of many bikes is different from size to size.

Take the Felt IA, for example. The larger the bike, the faster it is relative to the field. I believe I've seen Dave Koesel (he can't correct me if I'm incorrect) argue that the bigger size is faster than the smaller size, because the bigger airfoil of the Felt IA reduces drag at some yaws (even though surface area is larger). If that's indeed the case, then one bike might test better for a rider with a 600 armpad stack than might test for a rider with a 640 armpad stack.

Exactly, which makes the entire test pointless for anything other than a vanity project. Either you go frame-only (which is just a dick-measuring contest for those who based frame design on similar protocol), or you put a rider on and find the bike that works best for their position.

Think I'll save my pennies.
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Re: The Aero Bike Shootout: New vs. Old; Rim vs. Disc; Direct to Consumer vs. Retailer; Beam vs. Double Diamond (*an update*) [James Haycraft] [ In reply to ]
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James Haycraft wrote:
But at that point, what's the point at all?? If you can't normalize it to a reasonable degree based on: these are the bikes that fit me, I will test them how they fit me, and how I would use them for a 70.3....then what are any of us doing here at all? You can throw out essentially every single white paper and every aero test that anyone has done because it's not ME on MY bike.

I think you do as much as you can, and you run with it. You control what you can to a reasonable degree based on cost and time constraints as well as equipment availability. And then you have a pretty darn good test.
Is that what this data is going to be used for? So that the OP can make decisions as to what works for them? Or will the data be wielded forevermore to crack the skulls of nonbelievers?

I'm all for testing. I'm especially all for good testing. And I really hope this testing happens and applaud the OP for his effort in this endeavor. I applaud him for efforts to educate himself and others (even if his tactics aren't always the friendliest). But I think it's in everyone's best interests, including the OP's best interests, to approach this and the results it provides with skepticism.

I'll just say that, assuming the bikes being compared are set up the same, I'm more likely to find the data produced from runs without the rider to be of more value than the runs with the rider aboard. Others can decide as they see fit.

Trent Nix
Owned and operated Tri Shop
F.I.S.T. Advanced Certified Fitter | Retul Master Certified Fitter (back when those were things)
Last edited by: trentnix: Apr 12, 17 7:03
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Re: The Aero Bike Shootout: New vs. Old; Rim vs. Disc; Direct to Consumer vs. Retailer; Beam vs. Double Diamond (*an update*) [Slowman] [ In reply to ]
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just, to be clear, running a wind tunnel test is an art distinct from (say) being a fluid dynamics expert who doesn't have wind tunnel experience.

Just to be more clear since you obviously haven't understood or have bias against what I've written.

1. email me for the protocol to get what you are asking for. How hard is that to do? You want it, email for it. Problem solved. It's probably easier than shoeing a horse. (idk though never tried that but have used email a few times)

2. Do you think this is our first wind tunnel testing gig? If you do you should read your own website more often

EDIT: you also have a typo in your Giant review.

Brian Stover USAT LII
Accelerate3 Coaching
Insta

Last edited by: desert dude: Apr 12, 17 8:50
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Re: The Aero Bike Shootout: New vs. Old; Rim vs. Disc; Direct to Consumer vs. Retailer; Beam vs. Double Diamond (*an update*) [trentnix] [ In reply to ]
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*fwiw imo you should look at all data, including your own tests done on your own equipment with a healthy dose of skepticism. It'll keep you honest. (It's also why sharing your personal results from testing is often just a pitfall for other people who don't do their due diligence.)

More information is never a bad thing, especially good information tempered with common sense.

My Blog - http://leegoocrap.blogspot.com
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Re: The Aero Bike Shootout: New vs. Old; Rim vs. Disc; Direct to Consumer vs. Retailer; Beam vs. Double Diamond (*an update*) [Grill] [ In reply to ]
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Either you go frame-only.......or you put a rider on and find the bike that works best for their position.


Or there is a third option!

Brian Stover USAT LII
Accelerate3 Coaching
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