Ok, maybe the Diamondback example is a bad one. Tbh, I don't know much about the bike.

I completely agree that the protocol of optimizing each bike would be ridiculous and unrealistic! As I said, "prohibitively time consuming". The point I was trying to make is that this theoretical protocol may have yielded quite different and more useful results. But it's a moot point because that kind of public, independent testing will never happen with wind tunnels costing $500+/hr.

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

Outstanding! HED/Cervelo should be sending you a (couple) frames for selling them.. Can't wait to see how Specialized responds to this..

I've been using a standard BTA bottle since mid-2016. I don't doubt that the Torhans Aero 30 was quite fast, even with a gap between the head tube. In fact, I recall Jimmy telling me that a gap between the Aero 30 and head tube even appeared to be optimal, based on testing with several athletes.

I ditched the Torhans for two reasons. First, I experienced two failures, one of which was during a race causing me to lose all 800 calories of my fuel. Those bottles were well designed from an aero standpoint, but the mounting system and plastic quality was problematic. Maybe I just had a bad lot or it's since been rectified. Fueling is too important to screw around with, so I went back to a tried and true round bottle. Secondly, as I'm gearing up for longer races like ITU Worlds where I actually need to hit aid stations (unlike 70.3), it's way more convenient to have a standard bottle up front.

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

ah. yes. i actually do know this. i just got a little mind bent temporarily.

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Dan Empfield
aka Slowman

I'm glad you mentioned positioning. We could have run this test with me as the rider and gotten a different order in the results. I'm taller than Kiley. We could have used Heath who is even taller still and that may have changed things again or changed it back.

That's the one problem with this test is that it is most applicable to Kiley then less applicable but still relevant to people who can position themselves like Kiley rides then less applicable and less relevant the further you get from Kiley's position.

Cervelo's test with the mannequin has this same problem as well. The average triathlete rides more upright than Kiley or the mannequin which may or may not alter the results.

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

great post Dan. I agree with everything you have said. The reality is the P5X haters will never change their mind. Instead of saying Cervelo is lying, they will shift their attacks to price, looks, etc.

When the new Shiv comes out and has disc brakes, this argument will finally be over. For some of us, it probably won't ever be over.

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Make Inside Out Sports your next online tri shop! http://www.insideoutsports.com/

well, even if you have an identical fit to kiley in terms of AS/AR you're going to get different results because different musculature, morphology, body hair...etc. all kinds of shit.

The real takeaway from this is that it's a great test for one guy and it's really cool to see how relatively little difference he experienced between the different bikes (rider-off testing is useful but not definitive in any way). Those who choose to make purchasing decisions based off this test are honestly kidding themselves and rationalizing their desires. Which is totally fine. This and all wind tunnel testing used for any marketing (and this IS marketing) is just inherently flawed.

Everyone should run out and buy a P5.

I guess we all take different things from these results and what they mean. Personally I take from these results that my decision to sell my P5 and spend the savings on a P2 that I have optimized to save watts (and likely scarcely behind the P5), upgraded wheels and a power meter was money well spent. I think that is what everyone should be running out to do/buy.

lol.

Any test, no matter the industry, no matter the product, has limitations.

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Make Inside Out Sports your next online tri shop! http://www.insideoutsports.com/

i, as usual, don't understand your point.

Very interesting, rider on the p5-6 & p5-x are very similar, but take the rider off and the p5-x becomes significantly slower, almost the worst tested. (nb. I'm aware there were issues with the p5-x rider off data)

I wonder why that is? Is the p5-x rider on data similar for most riders? Or will some find the bike to be slower than the p5-6?

Either way thanks to the testers, much appreciated.

X2 lol

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"One Line Robert"

I'm not surprised at all.

Go talk to test engineers and understand how no matter what test you do, there are limitations in all testing. Sample sizes, test methodology, statistics, etc. One thing I've learned in hardware test, there is no perfect test.

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Make Inside Out Sports your next online tri shop! http://www.insideoutsports.com/

This doesn't surprise me at all.

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Make Inside Out Sports your next online tri shop! http://www.insideoutsports.com/

are you not surprised at all by my lack of understanding with regard to your point made in your reply to my post?

i'm completely aware of limitations to testing. unfortunately, my high school teachers didn't care.

Your post kind of implied wind tunnel testing is a waste of time.

I don't think it's a waste of time but it's just one test of many that need to be done in a design process. Perhaps the obvious CFD, maybe on road testing, and indoor velodrome.

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Make Inside Out Sports your next online tri shop! http://www.insideoutsports.com/

My post didn't "imply" anything of the sort. It implied that other people (people other than Kiley) using THIS wind tunnel test as a basis for their purchasing is flawed, because wind tunnel testing is incredibly specific. THAT is what makes it useful. The specificity. to YOU. Wind tunnel testing is INCREDIBLY useful. You can use this test to make general statements like "man, bikes sure are close these days," and "cervelo sure does make some good bikes," or "huh, looks like disc brakes aren't as completely terrible as some of us assumed they would be!" but to say "the Ventum is slower than the Tactical" and then buying the Tactical isn't really the right way of reading these results.

I think that they still did it a disservice by not giving it real suspension (especially for us older guys). Why would one waste a perfectly good cantilever?

Stephen J

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I believe my local reality has been violated.
____________________________________________
Happiness = Results / (Expectations)^2

No disagreement there. But for some people, this may be what they need to buy a bike. As long as they understand the limitations of the test, and how it obviously would be different than them, then let them buy what they want.

I'm happy the P5-X won. I knew it would.

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Make Inside Out Sports your next online tri shop! http://www.insideoutsports.com/

You're making me sound lazy.

You are right that the speed/power relationship does not scale linearly while time does. But that is the main reason why the equipment gains stay fairly similar.

Other factors:
Slower athlete has higher apparent wind angles so intersects a different part of the CdA curve
Generally, race days heat up and get windier. So a slower athlete has lower average air density, faster tyres and a further increase in apparent yaw
And, while the impact of aero stuff is greater as a percentage for faster athletes their speed gains are hard won (that non linear scaling) and the slower athlete is out there a lot longer to accrue gains.

Looking at Chattanooga 70.3 2016 (because there was more wind) - if we introduce slow Kiley with CdA 0.33, FTP 200w and consequent IF 0.725 (compared to 0.84) to keep TSS the same. He is riding 3.08 instead of 2.20. Going to a P5X from the B2 gives him a 91s advantage compared to the 87s advantage that actual Kiley would enjoy. Given the errors in testing we'd call that the same advantage. This holds for pretty much all the courses and sets of data I've worked with over the years - time difference is nearly constant.

One thing I wanted to have in the report was a comparison of fit ranges. Obviously that's a bit of a thing for me, but it's valid in this instance as not all these bikes fit equally for a range of people. Ventum with stock bars very limited, Andean very limited, Tactical better but I still need a bit more info to model that. P5 quite limited, P5X OK. B2 can do anything because it takes normal bars.Unfortunately I don't have data on all the bikes yet, nor have I had much time, so didn't submit that analysis.

And yes, the P5X with disc brakes has been vindicated. But give me another 9 months and the P5-3 (and possibly a P2) will be easily equaling it. For the aero part that was considered here.
Of course, that ignores wheels/tyres. I am limited in what I want to do with wheel design by the bikes that are currently available and the slow turnover of TT/Tri designs. So I agree that discs may allow us to eke out some tiny gains, but the testing methods will have to scale up to prove that.

The real takeaway from this is that it's a great test for one guy and it's really cool to see how relatively little difference he experienced between the different bikes (rider-off testing is useful but not definitive in any way).

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My only complaint is that this test seems like it's going to be taken as the gospel now of aero bike shootouts. Look at how even Dan/ST have covered this. Maybe this is Dan's way of "showing" Kiley how hard/frustrating/consuming aero testing is. But I'm hearing triathlon magazines are covering this event, etc. So I think while even Desert Dude said exactly your explanation that this is for Kiley more than anything; it sorta comes across as a end all be all, put up or shut up super bike showdown.


Or shall I say, it feels the same way the Sub Nike 2 hour thing went down. It was a controlled test, that you know Nike was going to market it so much differently post race, especially with how close they came to breaking 2 hours.

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Brooks Doughtie, M.S.
Exercise Physiology
-USAT Level II

Even P4 to P5 needs to consider this. P5-6 is much heavier than the P4 was - which narrows the gap even on flat courses.
Some data points for further context:
- From the P4 bottle testing a Speed Concept would be 27s slower with a round bottle on the frame (for Chatt 70.3 2017) for you
- For one of my riders going from a somewhat loose jersey to a tighter one made more of a difference than worst to best in this test
- As did going from Selector to Aerohead for that rider

.....or alternatively, imagine how fast that bike might or might not have been had disc brakes not been used ?

Go have fun talking with Tom A.

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I really am not sure the P5-X "wins" it all here. Like I was saying above, you can really only draw certain general conclusions from certain aspects of this test. One such generalization would be:

Holy crap, the Tactical, out of the box, wins this test by a fracking MILE. (and, to a certain extent, the B series with a bunch of aero parts swapped out)