That would be doing it twice. The plots ARE drag in the direction of travel for a given apparent wind angle already. It's only the component of the total drag force which acts along the axis of the bike.

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http://bikeblather.blogspot.com/

Yeah that very much too. Most places I'm aware of you're lucky if that is anything other than a permaban.

And... any thoughts on my actual aero question?

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The point is, ladies and gentleman, that speed, for lack of a better word, is good. Speed is right, Speed works. Speed clarifies, cuts through, and captures the essence of the evolutionary spirit.

I'm definitely watching. I'm not sure what info you are looking for but here is a graph showing our yaw distributions from the study.

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Chris Thornham
Co-Founder And Previous Owner Of FLO Cycling

I've only used BestBikeSplit as a trial, and I don't recall if you choose particular wheel model when selecting equipment or not...in any case, I do know that folks like cyclenutnz who do their own modeling keep quite the database of aero equipment and their drag vs. yaw plots.

But yeah...we have to remember that the wheels contribute a small fraction of the total drag in the first place, so the differences between them can easily be "lost in the noise" when comparing a model using steady-state drag data vs. actual results. Even so, the models do REALLY WELL when given quality inputs, so that "noise" is actually quite small.

Of course, all of that above ALSO makes me highly suspect of Hambini's testing, especially since he's supposedly testing with a live rider in a not very aero position in the first place.

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http://bikeblather.blogspot.com/

Right, but what dynamic pressure value are they using? I thought Kraig Willett stated years back that the LSWT corrected for dynamic pressure in the X direction. They didn't just use the tunnel value. Rather the measured X force and cos(yaw)*tunnel pressure were used to determine CdA.

Thanks, you did a great job of detailing your instrumentation and protocol here: http://flocycling.blogspot.com/...n-series-step-1.html

So you would have had traffic but I'm guessing not a lot? I also wondered how much the wind and yaw fluctuated; frequency and amplitude.

Chris,

If I'm reading your aero chart correctly, the difference between the 90mm and 60mm front wheel is 7 seconds over 180km. Is that correct? Seems very small.

We definitely did have some traffic and it's easy to see when that happens in the data. Visually the wind vane makes quite a jump while riding.

We are working with a new system right now that should produce much better data. I'm looking forward to crunching all of the numbers and sharing the data.

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Chris Thornham
Co-Founder And Previous Owner Of FLO Cycling

Yes it is very small. I actually just finished a blog article that will go live soon that mentions this. In Kona for example, the difference between a front 60 and 90 is one second.

Lately, on this forum, on our podcast, and in the latest blog article I've been talking about Small Magnitude and Large Magnitude changes. We've been suggesting that people worry about the large magnitude stuff and not focus on the small magnitude stuff—for 99% of us that is. Look for our latest blog article for a full explanation.

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Chris Thornham
Co-Founder And Previous Owner Of FLO Cycling

Right, they do the cosine beta squared correction on the data on the force values.

But now you've got me wondering about what I stated above about multiplying the CxA by the apparent wind speed^2, or the axial component^2...and I'm in no condition to work it out right now...sorry.

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http://bikeblather.blogspot.com/

I apologize if this has already been addressed but 14 pages is a lot to go through. I made it through 8. I am curious how spoke count and shape might influence the tests. It would seem rather important when comparing one wheel brand to another.

Thanks,

Jim

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Jim Lukanich

more spokes = more drag
rounder spokes = more drag
external nipple = more drag

importance ? a watt or 2 maybe

You're presupposing that we can make conclusions from the data. The stated experimental error is +-2.5%, which is +-15W for the 50km/hr case. And Josh Poertner (who has done a lot of WT tests at Zipp) doubts he achieved that with a full rider setup over months of testing.

A different study, but November Cycles did an aero test of CX-Ray spokes vs Laser and came up with a difference of 1W

https://novemberbicycles.com/...of-lasers-vs-cx-rays

Hi

I missed something, which charts are you referring too in order to derive this 7s delta ?

We've studied both of these items and have full reports on our blog. Here are the quick answers to your questions.

Spoke Count: These are the results of our standard build rear wheel with 24 spokes vs. our clydesdale build rear wheel with 28 spokes.




Spoke Shape: These are the results of Sapim CX-Ray spokes vs. round spokes. We use Sapim CX-Ray spokes in our wheels.





Take care,

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Chris Thornham
Co-Founder And Previous Owner Of FLO Cycling

Bit of a tangent, here, but I noticed the FLO 30 complete wheels have disappeared from the web store. Are your plans to only sell those as rims going forward?

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"They're made of latex, not nitroglycerin"

https://www.flocycling.com/aero.php

Scroll to bottom of page

We have discontinued the FLO 30s. The only rims left on the site are what we have left in stock. When those sell out, the product will be done.

Will there be a replacement aluminum product? Likely not. I'll never say never, but there are no current plans to update/re-release the product.

Take care,

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Chris Thornham
Co-Founder And Previous Owner Of FLO Cycling

Oh wow, Hambini delivers.
Updated post with Flo's letter.
https://www.hambini.com/blog/post/bicycle-wheel-aerodynamics-which-one-is-fastest/


That certainly doesn't looks good for you guys. It's a disappointing response regardless of Hambini questionable behavior.

Except for the fact that we never sent that letter. Neither did anyone representing us.

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Chris Thornham
Co-Founder And Previous Owner Of FLO Cycling

Then, it's defamation?

Dear Sir, I am a Nigerian Prince and kindly request your bank account to deposit you a sum of one million dollars.

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Eric Reid AeroFit | Instagram Portfolio
Aerodynamic Retul Bike Fitting

“You are experiencing the criminal coverup of a foreign backed fascist hostile takeover of a mafia shakedown of an authoritarian religious slow motion coup. Persuade people to vote for Democracy.”

The interesting thing is that that letter:

1) does not appear to demand the Flo results be taken down as originally claimed
2) contains no specific legal threat
3) instead requests HR discipline for use of company equipment and rude public behavior
4) their item 2 does not hold any legal water whatsoever
5) the first two instances of "see attached" have the A capitalized; the third does not
6) their item 3 does not have a period
7) their item 1 lacks a space between "3" and "hours"
8) is redacted as to the legal firm in question ("legal firm")

On that last point, I'm not a lawyer, but what expectation is there that a nastygram is private and revealing the "legal firm" in question would open the recipient to further action? Legal action is not private, so if "they" decided to follow through this would all be public anyway. Without the name of a company to follow up on this is no level of proof and doesn't even sound like any lawyer letter I've seen. It does, in fact, sound much more like Hambini's own writing style. If that's the case...

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The point is, ladies and gentleman, that speed, for lack of a better word, is good. Speed is right, Speed works. Speed clarifies, cuts through, and captures the essence of the evolutionary spirit.

If it's an internet stunt from Hambini, it's an insanely high risk stunt. He exposed himself, his career and his company to very real legal consequences. That would be a dumb thing to do.