The search function here and on biketechreview.com (forum run by the guys that run the San Diego Low Speed Wind Tunnel) will help tons in finding out the background of how bikes are measured and the basis on which we are discussing this set of data. Regarding your items:

4. Based on a bunch of historical data I'll go out on a limb here and say it was normalized to 25mph. Most of Hed's previous data for 30mph were listed starting at 0 deg yaw around 180-190g, which makes sense that this is around 120-125g at 0 deg yaw. These are pretty much the only two speeds ever used to display data.
5. You essentially said the only time aerodynamics of an individual wheel matters is if it's no longer attached to your bike. Andy Coggan's two posts on this very thread (along with thousands of hours of wind tunnel testing) shows that solo wheel testing is pretty darn well correlated to testing on the bike. There are obvious exceptions such as on funny bikes like the Trimble that Andy mentioned and of course the rear wheel has all sorts of issues with flow around the legs, etc. If you want to argue with Andy about it...good luck!!!

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Ummm... I don't think so. I believe that they are hired by the LSWT to help when cyclists come in (if you want them there). Dave Sanford runs the tunnel and is an employee of the San Diego Air and Space Technology Center.

http://lswt.com/contact.php

g

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greg
www.wattagetraining.com

FWIW, last year we tested a Zipp 999 wheelset against a competitor's set of wheels on my wife's bike with her aboard, and the results were consistent with what you'd predict based on wheel-only tests.[/quote]
And i think this is a lot more convincing. Showing that there is a difference even after you add the drag created by the rider creates a much more convincing argument to buy (i think).

Of course, you wouldn't want to do this if your wheels show no difference in this sort of test.

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mckenzie

Picky semantics. With the change in name I'm not sure if anything else has changed out there. But the measurement quality is likely to remain the same, and more importantly, just as relevant to the real world as it has been. Besides, how often have you known a website to have the wrong contact info? Heck, our company still shows "current product" that was discontinued 5 freakin years ago!

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Hello Andrew,

Your point is well taken, but I disagree with you in this case. Particularly in the 10-12.5-15 degree range for this particular test, the absolute magnitude of the measured force is very small, and the addition of a bike to the system has the potential to qualitatively change the results.

Triguy42, I did attempt to add some humor to the last point in my original reply. I apologize. The bit about the wheel crossing the line was an exaggeration meant as a joke; clearly, I was not successful there. I was not saying that front-wheel alone data is completely useless, but it needs to be treated with care. I have seen some interesting interaction effects, particularly at high yaw angles; I feel very uncomfortable drawing any strong conclusions from the data presented here.

Actually, the slower a rider goes, the greater positive impact of aerodynamic equipment. So if one assumes this fat, odd-pedaling, badly set up rider of yours is relatively slow, then the effects of good wheels will be that much more dramatic in terms of time saved.

Yes, I know you will scoff at this because it's counter-intuitive - and, frankly, I'm fine with it if you don't believe me.

I don't doubt your assessment, but frankly I don't care really. There are so many who think that you can buy the best bike, best wheels, best everything and suddenly you're a FOP rider. Sure, all of that might help, but in the end it's nto about the bike...

And, since you may think I am merely trashing ST'ers, I say the same thing about golfers too.

Bob

"There are so many who think that you can buy the best bike, best wheels, best everything and suddenly you're a FOP rider."

Really? You asked them?

C'mon. People aren't as stupid as you're making them out to be. Some ask some really crazy, newbie questions...but most are reasonably able to comprehend the simple concepts once explained. People want to know what is the best stuff out there. If the laymen out there sometimes struggle with the vocabulary, and then find out that their initial assumptions about some concept don't hold up to the science...well...that's to be expected.

Except, of course, for you, since you seem to be so damn smart about EVERYTHING.

I don't know diddly squat about golf...but I know that you could hand me Tiger's clubs and I'd still shoot 100+. I'm pretty sure the people asking questions about wheels this or frames that also realize that we could hand them Macca's or Fabian's bike but they wouldn't suddenly be winning IMH or Worlds and Olympic TTs.

DUH!

It must be exceptionally difficult for you living in such a dumbass world.

Jesus dude I hope you're not into sales because you need to work on your people skills.

My point is this: Golfers and ST'ers alike think that by buying the best shit, they'll be magically faster or better. Aside from the theoretical application of better aerodynamic equipment, not one person has disagreed with that statement. I made a statement based upon anecdotal evidence gather in races.

For instance, I've seen people in races riding a P3C with 40mm of spacers AND a high rise stem with a Zipp 999 wheel set up going 13 MPH. Additionally, I've seen people with about $7500 in golf equipment shoot 130 and blame something other than a bad swing.

I did not attack anyone on this forum, nor did I say a disparaging remark about anyone in particular. If, however, you'd like me to insult your dumb ass, as you did me, great I can do that, but I don't want to make you cry.

Bob

not really (picky part) - one guy is there for every run the tunnel sees (and gets the mindshare of all the testing - perhaps learning things that would then be applicable to bike testing from non-bike testing) while the other pair is there for bike testing only (and not all of that either).

wanna guess which of the above designed the much discussed fuji bike?

I dunno if what I wrote above is still fact or not, but it is the way things were when I talked to Dave last year.

I was not questioning the validity or experimental method of the data (which hasn't been disclosed - so kinda hard to challenge :) ).

As the current-ness of any website...dunno how to respond to that... :D

g

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greg
www.wattagetraining.com

Actually, buying the best shit is a very successful strategy for "magically" going faster (the hard part is identifying what actually is the best shit vis a vis the most expensive shit). Aside from the logical and analytic evidence, I can share quite a bit of personal anecdotal evidence about how good equipment selection has allowed a very much run of the mill rider (me) to get some results way beyond his ability. A few years back, before everyone got the TT bug and started shopping, I had a TT setup that was *so* good compared to what everyone else was riding, I could show up to a TT out of shape and be in the money anyway. I used to loan it to my teammates and friends - whose first ride on it would be to roll to the starting line - and they would ride personal bests on it (and sometimes beat me, on top of it). And I'm not telling you anything about the frame or any of the components other than to tell you that without wheels I managed to get the whole thing built up for less than $1k, with pretty much all of it coming from ebay.

In Reply To

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For instance, I've seen people in races riding a P3C with 40mm of spacers AND a high rise stem with a Zipp 999 wheel set up going 13 MPH.[/reply]
That's not a good example of buying the "best shit" - that's buying the most expensive shit. If you're making the argument that disposible income and bad decision making are somehow correlated wrt gear purchases, I'm inclined to agree with you.

I think the saying should go "Lies. Damn lies. Statistics. Wind Tunnel test results."

Determining the best is the most subjective exercise in the world. The best bike for me is a P2C due to the head tube height and biomechanical issues with my hamstring. The best bike for someone else might be a P3C or even a Specialized or a Trek...

But, yes, my larger point is that people equate buying the most expensive stuff with benig the best stuff and thus that which will make them faster and better. There is a guy at my LBS who has a Pinarello Montello FP3 (Or whatever the uber bike is) and he equates that with the best bike because it is the most expensive. All tolled he dropped on the order of $15,000 for a TT bike with a whacked out setup to make him comfortable (risers, tall stem, etc) and has never sniffed the podium once....

Bob

Fast wheels are fast wheels, period, and tunnel info is good information (probably the most valuable and pertinent information available to you and me, actually) to use when you go shopping for wheels. Being a misinformed luddite is every bit as sinful as being a misinformed spendthrift. And I believe this thread started on the topic of how effective these new Hed wheels seem to be. If you want to start a new thread making fun of dudes who spend their money stupidly, I'd be glad to join you - but we should definitely keep that discussion out of this thread.