Thus far, I'd purposely not mentioned that brand/wheel in hopes that nobody would ever consider buying a wheel made by a shady company that sounds suspiciously look "Yolo". I hear you with regards to this being a marketing ploy. That said, the results... the Shimano wheels in particular... seem too realistic to have been faked by someone who doesn't know that much about this stuff.

I will continue to buy Flo because they are transparent in their wind tunnel testing procedures.

Edited/fixed: not sure that's the same wheel as 2017 Aeolus 5 so don't know.

The *Pro* 5 is a new wheel that came out at the same time as the XXX though. I wonder how it compares to the old non-Pro models

Thanks for pointing that out! I'm going to delete my post because now I'm not sure it's the same wheel as last year.

That blog is totally not "realistic" there is nothing in it, numbers are "could be realistic" but the rest looks fake, except 2 random charts... anyone could come up with, just get the numbers 50-50% correct....
Having said that, those guys are doing carbon components for long time (they are not shady, since they are in business for long time), instead of trying to be the best, they should place them self just below (1-2W slower) Envy and Zip, with wheels that cost quarter of the price it would be no brainier choice for market their target. With current data posted they will just get laugh at. ENVY guys will get envy, zip guys will get zippy-zappy and everyone will call it BS. Otherwise none of Envy guys would even notice that blog, guys on the budget would still buy the product 1W slower and 70% less expensive.

They went to an awful lot of trouble and expense to come up with that really poor presentation.

What frame and fork were used? This has a big effect on wheel performance.
Why "relaxed hoods position" for aero wheels... and at 50km/hr?
Exactly how did they perform the "transient yaw angle" test, and what yaw angles were tested?
For a full rider on bike test we really need to see the repeatability.

I agree. The main reason I posted this was that I found it interesting that the Enve 7.8 and Bontrager Aeolus XXX 6 ended up so close to each other and that Flo, which has tested well elsewhere, tested so poorly. What I'm saying here is that maybe..... maybe.... something about this testing methodology, exposes strengths in some wheel designs and weaknesses in others that we have not previously seen.

Wait, so the people who did this test have a stake in one of the wheels tested? That's not clear to me from the site linked to.

I agree and I can't find a direct link... though that doesn't mean it shouldn't be ruled out.

Hey I know some guys who can do that haha

But what most people don't realize is that those dudes probably spent 20-50 hours planning everything before they ever set foot in the tunnel.

Like Jim said you'd need to devout some serious time tim finding the fastest wheel /tire combo. Then I suspect you'll need to redo that for every bike since fork blade are going to very in widths and blade widths won't be uniform either

Wind tunnel testing is waaaaaaaaaaaaaaay harder than most people think, even when we make it look easy.

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Brian Stover USAT LII
Accelerate3 Coaching
Insta

[quote desert dude Then I suspect you'll need to redo that for every bike since fork blade are going to very in widths and blade widths won't be uniform either[/quote]
This. It's a fun to look at these tests, but the wheel that is fastest by itself isn't necessarily going to be the fastest one in the frame. And the fastest wheel in once frame isn't going to be the fastest in another. Especially if you are looking at the difference between a beam bike which doesn't cover the back wheel at all versus a regular bike. Or between a tririg omni or ventum which there isn't a downtube and a cervelo p3 whose downtube is right behind the wheel.

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Matt

i'll 2nd that!
of course then you have frame/fork interactions but we'll ignore that for now...

my immediate reaction on seeing some no-name brand near the top of the results was that there is probably some influence there...

Jim@EROsports wrote:

Tire choice and pressure is absolutely crucial to any wheel testing and, for that reason, it's practically impossible to conduct a test like this properly. If you try to make the testing "fair" by using the same tire and pressure for each wheel, you've likely produced near meaningless data. There are simply too many variables; it would take weeks to test all the different combinations. Then, of course, you'll need to repeat those results to give them value. Fun!

I couldn't agree more, and it's the exact reason we've never done a FLO vs. Them study.


I have to say that I find it funny how the manufacturers are always made out to be the villains in these studies. As manufacturers, we certainly do not know everything, but I can tell you as a collective group, we have learned a lot about testing products. Honestly, most of us work together to help ensure the data we are producing is as good as possible. Some of the best advice we have ever received has come from our biggest competitors.


I'm not saying that all brands are 100% transparent and honest with their marketing, but I think most of our customers are smart enough to spot the fakers when they see them.


I think it's important for people to understand how the smallest changes in a wind tunnel can result in massive changes in drag. In most cases, these changes are so small or non-obvious that the people conducting the tests have no idea they are introducing error. Your protocol can render tens of thousands of dollars worth of wind tunnel time completely useless.


Independent and crowdsourced testing is great, but people need to pay close attention to their protocols and heaven forbid, ask the manufacturers for advice. Take the following as an example. There have been several crowd-sourced studies on this forum. One, in particular, added hundreds of grams of drag worth of error to their results in how they set up their tires. Yes, hundreds of grams in just the tires. Conclusion, the results are useless.


We own a $2,000 pressure sensor that we use for all of our studies. It's accurate to +/- 0.1 psi or better. Why? Because tire pressure is critically important. Had the people conducting the above study called and asked for advice, we would have gladly loaned them the pressure sensor, and in a single conversation eliminated hundreds of grams of error. Honestly, the more good data, the better.


A while back we contacted all of the brightest minds in our industry to create a Collective Testing Protocol (CTP) that all manufacturers could adhere to. The idea was to develop a standard protocol—available to the public—that eliminated as much error as possible. Wind tunnels could then become certified to conduct CTP studies, and your results would be stamped with a CTP logo by an independent 3rd party. We had 100% buy-in when we presented the idea, but when the actual work had to be done, most of the people backed out. I still have the wheel protocol somewhere.


Anyway, my moment on the soapbox is over. We'll be discussing all of this stuff in future podcasts simply because we think it's important to share what we've learned with our audience.

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Chris Thornham
Co-Founder And Previous Owner Of FLO Cycling

Why heaven forbid? That is what you do. That is what we did for the bike setups, anyways. That is what Cervelo did for their P5-X competitive testing -- well, according to Cervelo they did, which is an assertion Trek disputes.

But yeah, I think the way to find out the fastest configuration of tires, pressure, and wheels for testing is not by spending dozens of hours in the tunnel prior to the study (for each wheel) but to simply ask the manufacturer what that optimal configuration is. If they do not know or do not participate, that's a huge red flag, and it should be noted in the output. A control tire and pressure could be used for those.

There are still the variables that nobody will agree on. You have chosen to test wheel only, and apparently wheel only closely aligns with wheel in the bike, per Tom A. Maybe on the Dimond Superfork, but on the 3T Strada I find it impossible to believe that my ultra wide Enve 4.5 ARs together with respective tires and pressures tests much differently as a system in that fork, with its couple mm worth of clearance to the fork, than those wheels would in, say, the new Ceepo, among others.


I just don't believe you, but you know that, because I've told you that before. I do not believe tire setup accounted +/- more than 10 watts (roughly) worth of error. I call bullshit, again.

Separately, I do think it's basically chicken shit that you haven't tested your wheels against two of the industry leaders, say Enve and Zipp of equivalent depth, while soliciting the information from those companies for optimal configuration. For all the time and money you have spent in and on aero testing, I don't understand why you couldn't spare an hour to do very basic competitive testing in line with the instruction of your competition.

Besides all that, this study strikes me as a total waste. Here we are right on the verge of rim-brake systems being extinct, and they go out and test the wheels facing extinction. Which brings up the next question: how will we test disc brake wheels? In a bike or not in a bike? Am I supposed to believe the location of the caliper (i.e. what bike) does not have interplay with the wheel itself?

They brake fine, comparable to Firecrests etc. Just get some decent pads (Black Prince).

But even plus minus 10 watt is a lot

You just lost a lot of credibility right there. If anything it makes the test results presented here that more believable. If drag was that influenced by such slight changes in pressure, all published results would be meaningless on the road anyway.

I am still going to ask you to explain the rationale behing the impact of tire pressure on wheel aero drag.

They collected wind tunnel data a couple years back where they varied tire pressure from 90-105 psi in 5 psi increments on the same wheel and same tire and found some significant differences.

Link to blog post: http://flocycling.blogspot.com/...pressure-change.html

Why do we lose credibility for telling people that tire pressure is important? I think if people understand how important it is, they will be able to make better decisions when inflating their own tires.

Here's a simple example. Standard floor pumps can be accurate to +/- 8psi. That's a huge range. Better designed floor pumps are accurate to +/-1psi, and you can purchase high accuracy gauges for reasonable prices. If our customers know this, they can make better decisions when inflating their tires.

With respect to the rationale behind pressure having an impact on drag, the shape of your tire changes with changes in pressure. We have hundreds if not thousands of measurements showing this. Changes in shape have an effect on your drag. It's as simple as that.

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Chris Thornham
Co-Founder And Previous Owner Of FLO Cycling

The tire shape changes dramatically with pressure. Yes, we are chasing nearly unidentifiable differences between top wheels right now. 5psi matters. Read that blog post on Flo's blog.

I repeated did do a head to head in the wind tunnel. Same brand, size, model of tire at the same pressure except one was a few months old (less than 60 miles on the tires) showed notably different repeatable results just from being open and used. Head to head testing of wheels is something I won't attempt again since there are so many variables. I think to do it right, you need a very exact pressure gauge, same tire used on all the tests, etc.

This isn't "hundreds of grams of drag" difference though:


If tire selection and pressure are so important, then companies selling top tier wheels need to do the testing on multiple tires and pressures and give us the data so we can decide. Kudos to Flo for doing that better than anyone.

Pressure isn't the only variable to take into consideration when setting up your tires.

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Chris Thornham
Co-Founder And Previous Owner Of FLO Cycling

[quote]Why do we lose credibility for telling people that tire pressure is important?[/quote]

You don't lose credibility. It's moronic to suggest that imo

The problem becomes race morning or the night before when someone is pumping up their tires they'd have a better chance of finding a natural redhead escort selling payday bars while riding an elephant inside transition than you will finding a pump that's +/- 1psi.

What your data does provide is a range where people should be trying to get their tires to on race morning

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Brian Stover USAT LII
Accelerate3 Coaching
Insta