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Re: Kestrel Wind tunnel data [sharad] [ In reply to ]
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Is there a reason that you occasionally pop into this thread, defend your graphs with little to no data, then run away? Is it that difficult? Frankly, you're demeanor on this thread makes yourself and the rest of your company look like a bunch of idiots that think they can throw a pretty graph up and convince everyone.

You obviously paid a lot of money developing the bike, and a lot more testing. What's the difficulty in paying another several man hours to write up and release a decent white paper, and release photos? If your protocol was in fact as sound as you claim, then doing so will only help your cause.

Personally, I like the fit of this bike. I also like the fit of several other, similar bikes, which have been proven openly in the tunnel. I'm also looking for a fast bike for '10. As I stand right now, I love this bike, and will buy it in a heartbeat, if it can be shown to me that it's actually better than, or at least comparable to, the other bikes that fit similarly. With the data currently presented however, my view is that you have a sub-optimal bike, are fudging data to present otherwise, and as a result, I have zero interest in purchasing said bike. From that angle, the profit you would make off of me would cover the cost in man-hours for doing the writeup. Add in everyone else here, and the fact that many of us are considered at least local experts in aerodynamics, seems like an easy call.
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Re: Kestrel Wind tunnel data [Andrew V] [ In reply to ]
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+1
But then again, he only replies to Coggan and Tom A.

I think Steve should start a new thread to present the data in full - in his own words - and allow the "experts" their opinions, which excludes me.

Like he'll read this message.... anyway,......... :)
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Re: Kestrel Wind tunnel data [jmhtx] [ In reply to ]
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Man, once again I am not feeling the love in this post, it is funny how some of these posts really sink downhill in a hurry with some people's attitudes. I guess that Kestrel should have sent this over to joshatzipp or Gerald to post it so you guys would believe it without questioning it.
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Re: Kestrel Wind tunnel data [gralden] [ In reply to ]
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In Reply To:
Man, once again I am not feeling the love in this post, it is funny how some of these posts really sink downhill in a hurry with some people's attitudes. I guess that Kestrel should have sent this over to joshatzipp or Gerald to post it so you guys would believe it without questioning it.

Do you really think that they don't get peppered with questions too?

http://bikeblather.blogspot.com/
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Re: Kestrel Wind tunnel data [Tom A.] [ In reply to ]
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No Tom, I know that you guys give them the business too .. :o). This post just seems to be getting a bit rough as it goes on. I am sure Kestrel will supply more data, some of the folks just need to chill out a little bit, maybe training more would help relieve some of the stress.....
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Re: Kestrel Wind tunnel data [gralden] [ In reply to ]
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In Reply To:
No Tom, I know that you guys give them the business too .. :o). This post just seems to be getting a bit rough as it goes on. I am sure Kestrel will supply more data, some of the folks just need to chill out a little bit, maybe training more would help relieve some of the stress.....

Good...I was worried we were slipping... ;-)

http://bikeblather.blogspot.com/
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Re: Kestrel Wind tunnel data [Tom A.] [ In reply to ]
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I never worry about you slipping Tom, I actually enjoy your thoughts and comments, I now there is a ton that I can and have already learned here on ST. I know that you are one of the true 'local experts' that we have on here and that is what is needed. I am always just a little concerned when others say they are 'experts' but do not have the experience here on ST to back it up.

Not to hijack this thread, but what are your thoughts on the new Easton 90mm TT wheel shown at Interbike, I did not see any comments from you on this thread, but I know you must be thinking something .... ;o)

http://forum.slowtwitch.com/...earch_engine#2516790
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Re: Kestrel Wind tunnel data [gralden] [ In reply to ]
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In Reply To:
No Tom, I know that you guys give them the business too .. :o). This post just seems to be getting a bit rough as it goes on. I am sure Kestrel will supply more data, some of the folks just need to chill out a little bit, maybe training more would help relieve some of the stress.....

It's getting rough because there are good questions being asked with no answers arriving. This is Kestrel's fault. They are having their new premier aero frame being slammed due to some guy being too busy to answer questions.

Ken

Ps. I know that no one is actually slamming the frame but the company in my opinion looks quite Mickey Mouse right now, due to no defense of their data.


"the trick is to keep losing weight until your friends and family ask you if you've been sick. then you know you're within 10 pounds. if they start whispering to each other, wondering if you've got cancer or aids, you're within 5. when they actually do an intervention, you're at race weight." - Slowman
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Re: Kestrel Wind tunnel data [gralden] [ In reply to ]
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I have no douth that the new kestrel will be a excellent bike. I have big douth that it is as good as the graph is showing but i m sure it will be a good bike none the less.

Would just be nice to have more specific answer and details. I think that any company that make a commitement to triathlon as to commit one of there engineer to come here to present and explain the results. This site as too much influence in the tri market in north america to leave all those question unanswered. Cervelo, trek, felt, scott were at the top of the list at ironman hawaii bike count....and they competant and knowledgable people that come here every now and then to answer (accuratly and precisely) the questions..... i kind a see a partner in this....

As for the Easton 90mm TT. I played with it at interbike. The hubs were amazing...very small and smooth....as smooth as zipp. The wheel overall seems very nicely made but tubular only. I wonder if it really test as good as the graph show but i m very curious about it none the less...

Jonathan Caron / Professional Coach / ironman champions / age group world champions
Jonnyo Coaching
Instargram
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Re: Kestrel Wind tunnel data [gralden] [ In reply to ]
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In Reply To:
No Tom, I know that you guys give them the business too .. :o). This post just seems to be getting a bit rough as it goes on. I am sure Kestrel will supply more data, some of the folks just need to chill out a little bit, maybe training more would help relieve some of the stress.....
I think it got rough for two reasons.

1) there was a lot of talk beforehand about when the data would be released, how novel the testing concept was, etc. I.e., there was quite a bit of hype before anything was actually shown. Some bold claims were made about performance relative to very good bikes. So there was pretty big talk from Kestrel beforehand.

2) there was a LONG period of total silence from Kestrel with regards to the claims made above.

3) when the data was finally presented, it was very ambigious

4) even after the data was presented, explanations and clarifications of the data haven't been exactly forthcoming.

I don't think it's the data itself as much as what Andrew V alluded to - lack of communication, information, etc. that is reflecting poorly, IMO, upon Kestrel. Andrew V hit the nail on the head - they spent money on development, testing, etc. but couldn't hire someone to write up a 10 page white paper?

"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp
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Re: Kestrel Wind tunnel data [gralden] [ In reply to ]
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In Reply To:
I never worry about you slipping Tom, I actually enjoy your thoughts and comments, I now there is a ton that I can and have already learned here on ST. I know that you are one of the true 'local experts' that we have on here and that is what is needed. I am always just a little concerned when others say they are 'experts' but do not have the experience here on ST to back it up.

Not to hijack this thread, but what are your thoughts on the new Easton 90mm TT wheel shown at Interbike, I did not see any comments from you on this thread, but I know you must be thinking something .... ;o)

http://forum.slowtwitch.com/...earch_engine#2516790

I actually didn't look at those in Vegas...but, as others pointed out in the thread, how well it performs relative to similar wheels can be easily influenced by tire choice.

That said, narrow hubs and low spoke counts are rarely "bad" in regards to low drag ;-)

http://bikeblather.blogspot.com/
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Re: Kestrel Wind tunnel data [gralden] [ In reply to ]
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In Reply To:
This post just seems to be getting a bit rough as it goes on.

It's getting rough, because Kestrel's representative (Steve Harad) repeatedly pops in here, proves that he's paying attention, and seemingly deliberately ignores any relevant posts. Redo this exact thread, but with Felt, Cervelo, or Specialized, and I'm certain that Dave, Gerard, or Mark would be answering with real data and clarifications, instead of hand waving.
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Re: Kestrel Wind tunnel data [Andrew V] [ In reply to ]
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Andrew, these people (bike reps) do have real jobs and hanging out on message boards are more then likely not on the top of their lists of things to do during the day. I appriciate where you and others are coming from but Kestrel did not create this post (to toot their own horn), they are simple trying to respond when they can, just like all the others do when they have the time. Like I said, they will show more when they are good and ready I am sure.
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Re: Kestrel Wind tunnel data [gralden] [ In reply to ]
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He did find time to tell me that the data wasn't amateur, but ignored the quite simple question* I'd asked 4 times.

I appreciate that he probably has better things to do, but answering the most basic of questions about the testing would solve a lot of the problems.

*What speed the test was run at
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Re: Kestrel Wind tunnel data [zebragonzo] [ In reply to ]
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Gonzo, he might just be assuming that everyone knows that tunnel speed is 30mph for these kinds of bike tests, either that, or he does not like your name ... ;o), he hates zebras maybe.....
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Re: Kestrel Wind tunnel data [gralden] [ In reply to ]
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I realize that they didn't start this post, and that it's not their responsibility to constantly respond to it. There are my points:

1) If you competitors are spending the time to validate their data, be active in the community, etc., then it does become an expectation that, if you want to be treated on the same level, you will do the same.

2) Kestrel publicly released the graph. The data on the graph is suspect, and not well described. It is the responsibility of the company releasing the graph to provide adequate data to support it. It's not unreasonable to expect them to post a follow-up to the information, either as a press release, or some other way. They don't need to be directly answering our questions.

What Kestrel has done so far is similar to Ford providing an advertisement containing a graph of gas mileage, and claiming 70 mpg for the Focus. People would expect them to provide data supporting this claim (was this done in a vacuum? On the moon? With a strong tailwind? With all components removed except for the drive train?).
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Re: Kestrel Wind tunnel data [gralden] [ In reply to ]
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Gonzo, he might just be assuming that everyone knows that tunnel speed is 30mph for these kinds of bike tests, either that, or he does not like your name ... ;o), he hates zebras maybe.....

I reckon he's just got a bit of a man-crush on AC and Tom! :-P
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Re: Kestrel Wind tunnel data [zebragonzo] [ In reply to ]
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I just finished a little internet cruise through several of the wheel/frame manufacturers sties and came across what was, basically, the same type of data presentations (did see a few notes on speed and lots of curvy lines). You boys should probably do the same so that you can level some more of your angst and chagrin at a wider cast of conspirators! I am glad that I am a poor teacher who rides a "slow and obsolete" frame while placing the emphasis on my legs getting me to the finish line. The way I see it, I only have to train a little harder and smarter to make up for the time lost to those multi-thousand-dollar world-best frames that hit the market every year. I may be wrong, but at least I'm not getting worked into a frenzy! (I can't believe I read "F*@# off" on slowtwitch!)

http://stlifeontherun.blogspot.com
Official Polar Ambassador
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Re: Kestrel Wind tunnel data [chemteach] [ In reply to ]
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In Reply To:
I just finished a little internet cruise through several of the wheel/frame manufacturers sties and came across what was, basically, the same type of data presentations (did see a few notes on speed and lots of curvy lines). You boys should probably do the same so that you can level some more of your angst and chagrin at a wider cast of conspirators! I am glad that I am a poor teacher who rides a "slow and obsolete" frame while placing the emphasis on my legs getting me to the finish line. The way I see it, I only have to train a little harder and smarter to make up for the time lost to those multi-thousand-dollar world-best frames that hit the market every year. I may be wrong, but at least I'm not getting worked into a frenzy! (I can't believe I read "F*@# off" on slowtwitch!)


Well...we here at ST hold manufacturers to a "higher standard" ;-)

http://forum.slowtwitch.com/forumfaq.html

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SCIENTIFIC DATA: If the data is merely a reprint from another website or publication, all that is needed is a link or a reference to the original source (and as much information is provided by the original publisher).
If the data is coming from you, as a private individual, simply do your best to explain your testing protocol and methodology. You should be prepared to answer questions to the best of your ability.
If the data is coming from a company that you work for or are otherwise affiliated with, you need to explain your affiliation to that company. And you also need to provide adequate information to support the data which your are presenting. Whether or not that support is adequate is up to the judgment of our moderators. One guide is that if the data was being published by your competitor, what would you want to know? Another useful rule is that you should never reply to a question with the following, "Call X if you have a question"; you need to be able to explain what you have presented. Otherwise, you can't post it. If you have any questions about information you'd like to post, our moderators are always available to answer questions.

...and here's the thread where Rappstar expounded on this when the "rules" were implemented:

http://forum.slowtwitch.com/...resentation;#1999873


Now then, I believe that the OP in this thread is not affiliated with Kestrel, and merely followed the first part of the rule. However, I think that once someone who IS affiliated with Kestrel starts responding in regards to that posting of data, perhaps the third portion of the rules should be applied?

http://bikeblather.blogspot.com/
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Re: Kestrel Wind tunnel data [zebragonzo] [ In reply to ]
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In Reply To:
In Reply To:
Gonzo, he might just be assuming that everyone knows that tunnel speed is 30mph for these kinds of bike tests, either that, or he does not like your name ... ;o), he hates zebras maybe.....

I reckon he's just got a bit of a man-crush on AC and Tom! :-P

:-)

In point of fact, however, not once in this thread has Steve replied directly to me (and I have really only asked one question).
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An open letter to manufacturers [ In reply to ]
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Dear manufacturers,

On this forum, we often see data which is poorly presented and lacking information necessary to make it useful. Occasionally, we see good data.

To start with Cervélo made many a believer by ensuring that technical questions were not left un-answered. Trek then published a good white paper and they were considered serious contenders in the world of aerodynamics. Since then Specialized have got in on the game and their data is respected.

What all these companies have in common is that they release information that is sufficient to allow us to see what the data actually shows.

There are some basic things, which, if you cover, will save a lot of time by answering them at a latter date and will generally give us lot far more confidence in your data:
1) Where was the testing conducted?
2) Test protocol. eg. “Measurements taken by sweeping from 20° to 0° yaw. Wheels rotating”
3) Wind tunnel conditions. Speed is the main info you need to share. It would also be nice to know air density.
4) Bike setup. You may have tried to set the bikes up in the same way, but did you measure from the BB or ground?

The following information needs to be provided for each piece of equipment you test:
1) Date and time of test
2) Equipment used (eg. Wheels – 2007 zipp 808 clinchers with GP4000S tyres)
3) Bike size
4) Number of repeats of test
5) A photo would solve a lot of problems here, although I realise this may not be that easy

I look forwards to seeing test data with details attached in the future.

Rob T
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Re: Kestrel Wind tunnel data [gralden] [ In reply to ]
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In Reply To:
Andrew, these people (bike reps) do have real jobs and hanging out on message boards are more then likely not on the top of their lists of things to do during the day. I appriciate where you and others are coming from but Kestrel did not create this post (to toot their own horn), they are simple trying to respond when they can, just like all the others do when they have the time. Like I said, they will show more when they are good and ready I am sure.
Steven isn't a bike rep. He's the president of Kestrel. And you'd be amazed at the number of companies where keeping an eye on the various forums is at the top of the list of things to do during the day. Actually, maybe you wouldn't be amazed. Just go look at the brands atop the Kona bike count.

"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp
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Re: Kestrel Wind tunnel data [Tom A.] [ In reply to ]
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In Reply To:
Well...we here at ST hold manufacturers to a "higher standard" ;-)

That's right. No manufacturer may call any other manufacturer a "scl scntst"!

"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp
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Re: Kestrel Wind tunnel data [Rappstar] [ In reply to ]
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In Reply To:
In Reply To:
Well...we here at ST hold manufacturers to a "higher standard" ;-)

That's right. No manufacturer may call any other manufacturer a "scl scntst"!

Exactly...only the riff-raff are allowed to stoop that low ;-)

http://bikeblather.blogspot.com/
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Re: Kestrel Wind tunnel data [zebragonzo] [ In reply to ]
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"2) Scientists use straight lines, marketing people use curved lines; unless you know how the data varies between two points, assume it's linear"

Actually it is as wrong to assume linear data between points (straight line) as it is to use curved lines. I would argue scientists would use dots and would leave then unconnected.
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