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Kestrel Wind tunnel data
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From Xtri, the new 4000 v P3C and other in the Kestrel/Fuji family.



Suffer Well.
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Re: Kestrel Wind tunnel data [jmhtx] [ In reply to ]
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Really? How can you tell if that it's true? This whole aero arms race makes me dizzy.

customerjon @gmail.com is where information happens.
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Re: Kestrel Wind tunnel data [Mr. Tibbs] [ In reply to ]
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In Reply To:
Really? How can you tell if that it's true?
Well, you could use a powermeter to conduct some field tests, e.g., by riding laps around the velodrome in LA aboard a P3C or Fuji D6.
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Re: Kestrel Wind tunnel data [jmhtx] [ In reply to ]
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1) Why no P4?
2) If data was measured out to 30*, why is this data not reported?

That said... what wheels were used? I'd love to see a lot more information on this study before I declared it worthwhile at all.
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Re: Kestrel Wind tunnel data [Andrew Coggan] [ In reply to ]
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Can I use the Superdrome in Frisco.

customerjon @gmail.com is where information happens.
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Re: Kestrel Wind tunnel data [Mr. Tibbs] [ In reply to ]
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In Reply To:
Can I use the Superdrome in Frisco.
Absolutely. Just make sure to pick a really low wind morning (or evening).
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Re: Kestrel Wind tunnel data [Andrew Coggan] [ In reply to ]
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I'm all over it. Will have the data up in a few hours.

customerjon @gmail.com is where information happens.
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Re: Kestrel Wind tunnel data [Mr. Tibbs] [ In reply to ]
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In Reply To:
I'm all over it. Will have the data up in a few hours.

You've got a new 4000 at your disposal? Then by all means, go for it!

If you don't, then let me be the first to offer to field test one for Steve H/Kestrel... :-)
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Re: Kestrel Wind tunnel data [jmhtx] [ In reply to ]
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Well once again we see wind tunnel data that is in direct conflict with another. The cervelo data from last year when the P4 was released was not so nice to the Airfoil. And didn't some one say that the D-6 was the fastest bike in the world at 30 degrees? If so, why not include that.
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Re: Kestrel Wind tunnel data [Andrew Coggan] [ In reply to ]
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Just finished. I look sexy on all bikes.

customerjon @gmail.com is where information happens.
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Re: Kestrel Wind tunnel data [cbritri] [ In reply to ]
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It says at the bottom "Complete bicycles were tested as they would be recieved by the customer"

I wonder which of the 3 Kestrel 4000s they tested? The $10,000 version with Zipps? Against the $4500 P3 with stock shimano wheels?

Definately need more info.

-Adam

http://www.austintricyclist.com
Facebook http://www.facebook.com/austintricyclist
Twitter: http://twitter.com/#!/ATCTriShop

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Re: Kestrel Wind tunnel data [persondude27] [ In reply to ]
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In Reply To:
1) Why no P4?
2) If data was measured out to 30*, why is this data not reported?

That said... what wheels were used? I'd love to see a lot more information on this study before I declared it worthwhile at all.

I'm a bit surprised by these results - just because it's such a significant difference. With that said, I'm not really sure what they could've skewed here. Looking purely at P3 vs the 4000, as they fit similarly: aerobars, seats, wheels wouldn't seem to give one a significant advantage over the other.

Of course, they don't actually say whether they used the same wheels/bars/saddles/components on both bikes, or that the sizes were comparable, which could obviously skew the data (though it would be quite dishonest).

Also, according to cervelo's data, the P3 tests at ~700g of drag (0 yaw), the P4 at 575. cervelo also shows the P4 as worse at 10 yaw than 15, which kestrel doesn't. Kestrel has the P3 testing at 850g. Protocols can be skewed, but the final numbers can't, and the fact that cervelo could get 150g better than Kestrel definitely implies that the P3 was set up in some non-optimal way.
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Re: Kestrel Wind tunnel data [ATC] [ In reply to ]
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good points. Even ignoring wheels, the P3 comes stock with non-aero cranks, pretty low-end aluminum base bar upturned, and significantly upturned extensions, which would all test poorly. Anyone looking at buying any of the new high-end bikes would likely replace all of that anyway.
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Re: Kestrel Wind tunnel data [ATC] [ In reply to ]
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Well, since you guys can get all of the bikes tested...let's get them, go to TAMU with Mr. Cobb, and see which one is fastest. We can grab a Felt from down the street too. And we can probably get a TTX and Transition from down the street at the other place too.

Can we start a ST.com fund for the testing?


Brandon Marsh - Website | @BrandonMarshTX | RokaSports | 1stEndurance | ATC Bikeshop |
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Re: Kestrel Wind tunnel data [-Tex] [ In reply to ]
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Lets see what I have laying around:

Don's P4
George's P3
My E-114
Cannondale Slice

So we need A kestrel 4000, A Felt DA, and TTX.

Also I need around the clock security just in case one of these bike companies trys to stop us.

-Adam

http://www.austintricyclist.com
Facebook http://www.facebook.com/austintricyclist
Twitter: http://twitter.com/#!/ATCTriShop

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Re: Kestrel Wind tunnel data [ATC] [ In reply to ]
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You know, we could have this conversation over the phone. But, I am kind of serious.

I think that John has some tunnel time in November. If the ST brain trust (or forum junkies) were interested, and we could come up with some donations...it'd be a fun test.

Same bars and bar position, same seat height, clip off all the cables, same wheels, etc. and run them through the 0-15 (or whatever) yaw and be done with it.


Brandon Marsh - Website | @BrandonMarshTX | RokaSports | 1stEndurance | ATC Bikeshop |
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Re: Kestrel Wind tunnel data [-Tex] [ In reply to ]
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In Reply To:
Same bars and bar position, same seat height, clip off all the cables, same wheels, etc. and run them through the 0-15 (or whatever) yaw and be done with it.
Although it would make things more expensive, I would advocate testing the bikes with cables in place - after all, many of the newer designs attempt to reduce drag by hiding/relocating the cables, such that leaving them off might bias the data.
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Re: Kestrel Wind tunnel data [-Tex] [ In reply to ]
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We have the bikes, the mechanics, and the time. All we need now are some funds....

http://www.austintricyclist.com
Facebook http://www.facebook.com/austintricyclist
Twitter: http://twitter.com/#!/ATCTriShop

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Re: Kestrel Wind tunnel data [ATC] [ In reply to ]
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In Reply To:
It says at the bottom "Complete bicycles were tested as they would be recieved by the customer"

I wonder which of the 3 Kestrel 4000s they tested? The $10,000 version with Zipps? Against the $4500 P3 with stock shimano wheels?

Definately need more info.

-Adam

That was my first thought exactly when I read that part....sigh...I really hope that's not the case.

http://bikeblather.blogspot.com/
Last edited by: Tom A.: Oct 7, 09 16:35
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Re: Kestrel Wind tunnel data [Tom A.] [ In reply to ]
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You guys realize this is just marketing, right?
I mean, what company is going to come out and say "Hey, we'd like it if you buy our bikes, but really brands x, y, and z are all faster than ours".
It isn't about telling the truth, it's about selling a product.
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Re: Kestrel Wind tunnel data [ndenezzo] [ In reply to ]
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In Reply To:
You guys realize this is just marketing, right?
I mean, what company is going to come out and say "Hey, we'd like it if you buy our bikes, but really brands x, y, and z are all faster than ours".
It isn't about telling the truth, it's about selling a product.

Marketing is all well and good...but when wheels can be readily changed between framesets, and TT/Triathlon bikes are commonly sold with just "training wheels" (with the assumption that the buyer will be putting on his own race wheels), IF the test actually DID consist of testing the Kestrel with a deep Zipp wheelset vs. a P3 with a low profile wheelset, well that starts crossing the line into intentional obfuscation.

If you have a good product to sell, you don't need to stoop to such things to effectively sell it...

Did you notice that when Mark Cote revealed the tunnel data on the Shiv in comparison to the Transition (and previously Transition vs. P3) that the testing was done with the same wheelset between the bikes?

http://bikeblather.blogspot.com/
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Re: Kestrel Wind tunnel data [Tom A.] [ In reply to ]
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If you have a good product to sell, you don't need to stoop to such things to effectively sell it...

True, but I'm a cynical person by nature, and I don't really trust anything given by the company selling it.
Cervelo, Specialized, Giant, Trek, Kestrel, Felt, they all have "data" that proves their bike is faster than everybody else's. But someone must be doing something to skew the data, because they can't all have the "fastest" bike.
Same with Zipp vs HED vs Reynolds vs Blackwell, etc.
Everybody has data to prove their stuff is better than what the other guys are selling.
If there's data from an independent source, I'm much more likely to believe that than anything a company tells me. Sure, a good company should be honest, but selling products seems to come first.


EDIT: I'm not saying Kestrel did or didn't do anything shady here. I highly doubt they would have done something so drastic as use deep dish wheels on their bike, and box rims on the others. The cynic in me just thinks that any company will do small things to make their bike come out on top in testing.
Last edited by: ndenezzo: Oct 7, 09 17:25
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Re: Kestrel Wind tunnel data [ATC] [ In reply to ]
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"I wonder which of the 3 Kestrel 4000s they tested? The $10,000 version with Zipps? Against the $4500 P3 with stock shimano wheels?"

Ummmm...ok...yeah, they don't say specifically on this chart....but it would be a stretch to think Kestrel would jeapordize their reputation putting out data that would be roundly ridiculed and recognized as a poor effort at making their product falsely stand above other NAMED manufacturers. No reputable manufacturer is going to make such a blatant attempt in the days of internet gossip fires.

Also, IIRC Sharad has already posted details on the testing in some thread here...
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Re: Kestrel Wind tunnel data [-Tex] [ In reply to ]
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Can we start a ST.com fund for the testing?
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I'm in for $27.

Brian Stover USAT LII
Accelerate3 Coaching
Insta

Last edited by: desert dude: Oct 7, 09 17:34
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Re: Kestrel Wind tunnel data [TriBriGuy] [ In reply to ]
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Also, IIRC Sharad has already posted details on the testing in some thread here...

Nope...but this was on xtri.com:

http://www.xtri.com/...p;CAT=21&xref=xx

Sounds to me like they DID test the P3 with the Shimano R-550 wheels. So, it remains to be seen which "level" of 4000 was tested against it, the LTD (which comes with an 808/1080 set) or the SL model (Ksyrium Elites).

BTW, I have to respectfully disagree with Mr. Harad that they have come up with "the standard on testing" in using bikes "as spec'd" for the testing. That would make sense if the buyers weren't allowed to switch wheels, bars, or saddles even when racing.

http://bikeblather.blogspot.com/
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