Open mold wide profile carbon wheels

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NovemberDave
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by NovemberDave

Thanks, had never seen a hub comparison before and I'll take that one at its word. Their comparison of round versus bladed (which is actually specifically straight gauge 2.0 vs DT Aerolite) is more in line with what we found with Laser vs CX Ray and understated compared to Flo's straight gauge vs CX Ray test. The test we ran with the pen cap, and what Zipp has said with respect to hidden nipples (they say no effect at all), disagrees with the magnitude of impact they show with hidden nipples, but their info agrees with what Enve has said. No consensus on that one.

Overwhelmingly, wow those wheels are not very low drag! But that comes back to what I've come to believe in - when a HED Belgium+ is within speaking distance of a 303 after the wind tunnel 40k, the whole "aero wheels can turn you into a new rider!!!" hyperbole seems, well, weak.

On next post and our graph - Kinlin is 19mm inside width so it inflates tires wider than Zipp, as does Al33. 303 overall width is wider than either, so given that it inflates tires smaller against a wider overall width, that contradicts blanket statements about tire width versus rim width.

There are differences beyond depth that occur with the 303/Kinlin/Al33/others so you sure couldn't isolate the 303's better high yaw performance to depth. Flo30 has the most toroidal shape of all these rims, was relatively bad head on and relatively better at wide yaw.

For yaw angle distribution, the Flo and Trek analyses that we refer to in that series of posts are "case closed" for me. Also bear in mind that effective yaw angle closes down A TON when you draft because the actual wind's speed is slowed so much that its contribution to your apparent wind vector is much diminished.

bilwit
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by bilwit

bike being 25% and wheels only 8% of overall drag is pretty eye opening to me, some reason I always thought wheels had a much more significant effect than the frame :noidea:

by Weenie


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Beaver
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by Beaver

Internal nipples: Easton said there is a difference and the EC90SL had internal nipples at first, then they went back to external because the mechanics complained. :D

Roval also said they didn't measure any difference with internal nipples - but they are there and they will have an effect, even if it is the tiniest one of all. ;)

Back to your test, I think it should be explainable, if we have a look at the rims:

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The Flo 30 seems to have the worst transition between tire and rim, followed by Zipp - after the tire there is the torodial bulge, the others don't have and are therefore better in the low angles, I would guess. With a tire slimmer than the brake track, there should be a better outcome for the torodial shapes. :noidea:
Last edited by Beaver on Wed May 16, 2018 8:45 pm, edited 1 time in total.

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Beaver
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by Beaver

bilwit wrote:
Wed May 16, 2018 8:20 pm
bike being 25% and wheels only 8% of overall drag is pretty eye opening to me, some reason I always thought wheels had a much more significant effect than the frame :noidea:
That's what I thought before, too. And others: :D

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EDIT: They meant bike with wheels 25%, because 75+25+8% would be 108%. :mrgreen: But nevertheless 17% bike, 8% wheels. Still twice as much as the wheels.

But might be on par with the Tour Mag. tests: with the bikes (with wheels ;) ) the diffences are around 34 watts (F10 with 404 FC vs Emonda SL with Aeolus3), while the wheels only have 14 watts (404 FC vs. Ksyrium Pro) at max. - 404 FC vs. Aeolus3 are a few watts only. So there is really more potential in the frame. And I guess optimizing frame and wheels as a pair would also make sense.
Last edited by Beaver on Thu May 17, 2018 10:53 am, edited 2 times in total.

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Beaver
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by Beaver

And maybe a short look at this (the side with the disc is worse btw. :mrgreen: ):

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Reynolds Aero 46 DB: 19C, 46x28mm, 20 spokes, internal nipples
Zipp 303 FC Disc: 21C, 45x29.9mm, 24 spokes, external nipples
DT Swiss ERC 1100 Dicut: 19C, 47x27mm, 24 spokes, internal nipples

Low angles: 28mm tire on dicut has the largest frontal area, so worst, fits. Reynolds with 25mm tire has the same frontal area as Dicut, but less spokes, so best, fits. Interestingly Dicut with 25mm tire is worse than Zipp 303 here, although the Zipp is 2.9mm wider. Does anyone know how wide the rim is at the brake track? If it's around 28mm there would be a much better transistion than with 303 rim brake and torodial really "needed" a slimmer tire to perform well in low angles.

High angles: torodial shape is best, Reynolds worst, as we also saw in the Tour test and an overlapping tire destroys the aero benefits of the Dicut. And I would presume the new 21C Bontrager 4 or 21C Light Bicycle 46x28mm would be somewhere in between. Light Bicycle with 20 spokes and internal nipples maybe even best overall.

But as always: one digit watt differences of 450 watt needed overall. Unnoticable in real life. It's just a theoretical playground. ;)

Crosswind stability without overlapping tires or a 25mm tire on 21C with low pressure on bad roads does help more.

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Beaver
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by Beaver

https://industrynine.com/road/i935-disc

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And the next one. :mrgreen: 21C and 29mm outside, rim design by Reynolds but not as "sharp" as their own wheels.

https://docs.google.com/document/d/1-eN ... Hc7wE/edit

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"Significantly faster." :smartass: :mrgreen: 2 watts of 450 watts.
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Beaver
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by Beaver

Image

There's also an aero wheel review in the June edition of German RennRad magazine.

They tested wheels with around 50mm rims. 4 watts difference, Lightweight was last, as usual. ;)

At least they also stated that lowering your head by 5 centimeters equals 5 watts...

NovemberDave
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by NovemberDave

Thank you for emphasizing the actual objective differences. Sensationalized subjective measurements do a disservice to the actual audience - the riders. I am maybe not the smoothest rider in the world, but I was absolutely not able to keep myself within a 5 watt window when I rode in the tunnel (it's hard, try it some time!).

The test that Tour Magazin did in issue 6 or 8 (can't remember) of 2016, which tested everything from a Ksyrium (worst) to a 58mm Zipp 404 and a 66mm DT Swiss (equal best) showed a 13w difference from worst to first. I'd rather have 13w than not, but when phrases like "lightning in a bottle!" (my all time favorite) and "absolute game changer" get thrown around, I tend to think of something more watts than I can count on one hand, or exceed by improving the way I buckle my helmet. From memory, 404 to Shimano C50 was 2w, and to Bora was 3w, to 303 and a pile of others it was 3w, etc.

My issue isn't with companies trying to do better - I think we all do - but rather with the hyperbolic subjective language that misleads and frustrates consumers.

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Calnago
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by Calnago

Here here! But the consumers keep lapping that stuff up as if they can actually tell the difference between 3w and 5w. And as long as they keep lapping it up without question, the “game changing” rhetoric will continue. If I can feel it on the road, it’s real. If I can’t, then it may still be “real” and able to be shown on an appropriately scaled graph of sorts, but it’s not real enough for me to base a decision solely upon.
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
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pushstart
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by pushstart

Yeah, +1. Thanks for keeping it real, NobemberDave!

I think there is so much else that one "feels" when you're trying out that new set of wheels -- how they transmit the road, how stiff they are under power, how they feel in crosswinds, the sound they make, the way they change the tire profile, etc. -- that noticing the few watts of aerodynamic gains (or losses) really doesn't seem very likely for anyone not applying some serious rigor to their riding position/power/etc.

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kavitator
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by kavitator

Sound :beerchug:

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Beaver
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by Beaver

NovemberDave wrote:
Fri May 18, 2018 9:44 pm
Thank you for emphasizing the actual objective differences. Sensationalized subjective measurements do a disservice to the actual audience - the riders. I am maybe not the smoothest rider in the world, but I was absolutely not able to keep myself within a 5 watt window when I rode in the tunnel (it's hard, try it some time!).

The test that Tour Magazin did in issue 6 or 8 (can't remember) of 2016, which tested everything from a Ksyrium (worst) to a 58mm Zipp 404 and a 66mm DT Swiss (equal best) showed a 13w difference from worst to first. I'd rather have 13w than not, but when phrases like "lightning in a bottle!" (my all time favorite) and "absolute game changer" get thrown around, I tend to think of something more watts than I can count on one hand, or exceed by improving the way I buckle my helmet. From memory, 404 to Shimano C50 was 2w, and to Bora was 3w, to 303 and a pile of others it was 3w, etc.

My issue isn't with companies trying to do better - I think we all do - but rather with the hyperbolic subjective language that misleads and frustrates consumers.
http://www.tour-magazin.de/komponenten/ ... 41647.html

That was Tour issue 8/2016 and the reason I started thinking about this whole topic. In the annotations they wrote, that the data was without a real rider, so I checked the power needed at 45km/h and 35km/h (450/225 watts in the drops) - the already really small diffences were indeed tiny.

And RennRad Mag. now gave the power needed for the wheels only, so that were 74 to 78 watts - sounds much better than e. g. 446 to 450 watts... And the "best" way is to only show the differences like Industry Nine did in the graph above. That looks as if only half the power is needed with their wheels. If the y-axis would show the real power needed overall from 0 to 450 watts, the lines for the different wheels would all lay exactly one upon the other and could not be kept apart from each other.

I hope more and more people will unterstand this and question the marketing.

But the bike tests showed that there is also a little more potential (30 watts) in the rest of the bike, so overall maybe 45 watts for an Pinarello F10/Zipp 404 FC vs. Trek Émonda/Mavic Ksyrium Pro. That's 10% of the power and 1 km/h at 45km/h but won't help me win the Tour de France either. ;) For a pro this is about win or loose and makes sense, for everyday riders not so.

And last one: in the current Tour issue there is a tire test again and again there are only very small differences between the "top tires" - interestingly they wrote that slim tires on very wide rims are wobbly, and e. g. a 25mm tire on 21C doesn't make sense. For their recommendations the orientated on Mavic and DT Swiss. :unbelievable: Orbea sells 23mm tires on 19C rims on their stock bikes, Specialized 26mm on 21C since for more than a year now... The industry lives by continuous small changes. ;)

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Beaver
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by Beaver

Hm, the differences are even not that important for the pros (but in the group, you are not facing the wind alone):

https://www.youtube.com/watch?v=nmJpHQsITTs

And here Hambini compares a Kamm tail profile and NACA profile for frame tubes at 10° yaw:

http://www.youtube.com/watch?v=QqX3juRttP4&t=4m26s

But the shapes are quite close to a torodial and sharp V-shape rim - maybe this can be transfered and explains why Reynolds rims are more stable in crosswinds than e.g. Zipp.

It's oversimplification again, but would fit. :mrgreen:

With the Kamm tail shape you can also see higher forces on the side facing the wind (red/yellow area at the "bottom"), with NACA there are none.

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Regarding areodynamics, the NACA profile has a larger red/yellow area on the the wind averted side ("on the top") and should therefore cause more drag. The turbulences in the airstreem Hambini mentions and which occur "further back" won't be an issue with a wheel, because the turbulences of the spokes are in between.
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morganb
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by morganb

Is there an open mold manufacturer known for good braking, or at least is there one superior between Light Bikes, Yishun, Farsports, etc?

by Weenie


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Beaver
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by Beaver

The older rims used a Basalt coating (clear black surface), which didn't last long and could cause overheating. Meanwhile they all use a woven carbon-basalt brake track (looks like 3k carbon). For better braking in the wet you will need a machined/textured brake track as found on Mavic, Zipp, Enve, Campa/Fulrum rims. So don't expect big differences between those open mold rims (or a DT Swiss rim, that uses the same).

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