wheel test--cycling weekly--from ww---surprising results

[chrisroph]

In the latest issue of the comic there is a big wheel test - 18 different wheels (8 tub, 10 clincher).
tub:
Bonty Aeolus
Easton T2 carbon
Lightweight standard
Controltech Carbon Comp
Fulcrum Racing Speed
Cosmic Carbone Pro
Reynolds DV-UL
Zipp 404

clincher:
Neutron
Easton T2
Shamal Ultra
FSA RD-600
Fulcrum Racing Zero
Roval Fusee
Roval Fusee Star
Spinergy Stealth PBO
Ksyrium ES
Zipp 303 Clincher

Tested on a track using SRM cranks.

RESULTS

tubs:
Reynolds
Cosmic +4.2W
Fulcrum +4.44W
LW +11W
Zipp +11.3W
Control-Tech +11.6W
T2 carbon +12.6W
Bonty +17.7W

clincher:
Neutron
Shamal +6W
Zipp +6.2W
Fulcrum +6.3W
Spinergy +6.5W
T2 +6.5W
FSA +6.5W
Fusee +8.1W
Fusee Star +8.8W
Ksyrium +10.6W

[Richard]

My assumption is that it takes 17.7 W more to make the Bonty go as fast as the Reynolds. Correct?

[BumbleBeeDave]

. . . forgive my denseness, but what are the measurements referring to? Is that how many watts it takes to keep each one rolling?

Does this mean that with the clinchers, for instance, it takes 10.6 watts more to keep the Ksyrium ES's rolling than it does to keep the Neutrons rolling? And is there any way to compare the clincher wheels to the tubular wheels? And were all these clincher rims shod with the same tires? Same for the tubies?

BBD

[Tom]

Of course they didn't use the same tires. Some had Conti Gatorskins, some had PR2s, for example, on the clinchers. Weight of tires is completely immaterial in a test like this.

[shinomaster]

Chris where did you find these results?

[BumbleBeeDave]

Of course they didn't use the same tires. Some had Conti Gatorskins, some had PR2s, for example, on the clinchers. Weight of tires is completely immaterial in a test like this.

. . . of rolling resistance. But it seems to me that any comparison is bound to be more fair and accurate if you elimnate as many variables as possible.

BBD

[Volant]

Any way to reprint the article or provide a link?

[dauwhe]

Of course they didn't use the same tires. Some had Conti Gatorskins, some had PR2s, for example, on the clinchers. Weight of tires is completely immaterial in a test like this.

I'm not sure I understand--if different wheels had different tires, differences in the rolling resistance of the tires would certainly affect the test results.

I can't imagine why they wouldn't use the same tires on all clincher wheels.

Dave

[J.Greene]

Was there a speed mentioned?

[Tom]

And they tied small furry rodents to the spokes on some wheels and armadillos to the spokes of other wheels.

[fiamme red]

Where do square wheels fit into the picture? Or triangular ones?

[Tom]

Oop, sorry. They tied hedgehogs to some wheels and stoats to the others.

[chrisroph]

All good q's. Here is the link. The test apparently involved using sram data on bikes being pedaled around a track at 48kpm with no wind. It is quite interesting although the test allegedly uses somewhat questionable protocol. Somebody said the tires were all vittoria cx, tubular and clincher. I was also wondering about an absolute comparison between tubular and clincher. I'd like to see the underlying article. I know the nucs are good wheels, I've got 4 pairs. I still think the strongest guy wins, regardless of wheels, especially in a mass start event.

[oracle]

ksyrium's = pre-installed turbo trainer

[Tom]

...bikes being pedaled around a track at 48kpm with no wind...

Gracious, they were going fast.

[shinomaster]

ksyrium's = pre-installed turbo trainer


I thought K's were fast?

[stevep]

i want to see the curve that goes from 23mph to the 32mph or so that they used.
i bet its steep at the top end.

this stuff makes little or no dif to very many people here.
if yr going 30 you are likely with other riders, etc, etc
if yr riding along pretty hard at 23-25 the aero effect ain't that high.

thats my opinion.

[stevep]

I thought K's were fast?

depends on whose using them shino.

[gt6267a]

so ... i should keep my nucleons?

[Tobias]

if yr riding along pretty hard at 23-25 the aero effect ain't that high.

thats my opinion.
:confused: Do you mean the total aero effect or that which is contributed only by the wheels?

My understanding is that at about 20 MPH wind drag is about 4 times higher than rolling resistance for a man my size.

[Tom]

My understanding is that at about 20 MPH wind drag is about 4 times higher than rolling resistance for a man my size.

That's strange. I would have been willing to bet that it's harder to roll you over.

[stevep]

:confused: Do you mean the total aero effect or that which is contributed only by the wheels?

My understanding is that at about 20 MPH wind drag is about 4 times higher than rolling resistance for a man my size.

we are measuring the wheels, natch.

but rolling resistance is more or less negligible.
drag is what yr fighting.. at almost any speed.

[Lifelover]

i want to see the curve that goes from 23mph to the 32mph or so that they used.
i bet its steep at the top end.

this stuff makes little or no dif to very many people here.
if yr going 30 you are likely with other riders, etc, etc
if yr riding along pretty hard at 23-25 the aero effect ain't that high.

thats my opinion.

That is not just your opinion, It's the truth!

[chrisroph]

i want to see the curve that goes from 23mph to the 32mph or so that they used.
i bet its steep at the top end.

this stuff makes little or no dif to very many people here.
if yr going 30 you are likely with other riders, etc, etc
if yr riding along pretty hard at 23-25 the aero effect ain't that high.

thats my opinion.

I agree but I do feel (subjectively) that my tt bike with the trimmings is worth a mph or 2 in the 25-29 mph zone. And it goes 42-43 down a local hill I can down coast on a regular bike at 39.

[RPS]

I agree but I do feel (subjectively) that my tt bike with the trimmings is worth a mph or 2 in the 25-29 mph zone. And it goes 42-43 down a local hill I can down coast on a regular bike at 39.
Do you sit the same on both bikes? Most time trial bikes I've seen have the rider in a much more aero position, which could account for the higher speed independent of the wheels.

If possible try it after swapping the wheels. That might give you more info.

[RPS]

if yr riding along pretty hard at 23-25 the aero effect ain't that high.

thats my opinion.
If not the aero effect, then what is making you ride hard?

I'd agree that the wheels are a small part of total aero drag, but they are only talking about relatively small changes in the range of 5 to 10 watts for the most part.

[RPS]

That's strange. I would have been willing to bet that it's harder to roll you over.With the right circumference he may roll over easily. ;)

[rpm]

The results seem bogus to me. The Bontrager was designed by Hed, and those guys are serious about aero stuff.

[shinomaster]

Chris is this some sort of lame stunt to get one of us your used Neutrons?

SteveP What if I was using them?

[chrisroph]

Do you sit the same on both bikes? Most time trial bikes I've seen have the rider in a much more aero position, which could account for the higher speed independent of the wheels.

If possible try it after swapping the wheels. That might give you more info.

No, the aero position with the geek bars is part of the equation. On the training rides I describe, I use regular non-aero wheels. Most of the difference is in the position change.

[chrisroph]

[QUOTE=shinomaster]Chris is this some sort of lame stunt to get one of us your used Neutrons?

[QUOTE]

Nope. If somebody makes me an offer I can't refuse I'll sell them. Otherwise, I'll just keep them. A guy can't have too many nucs. And they're more aero than zipps!!

[stevep]

SteveP What if I was using them?

shino,
if you were using them you'd ride effortlessly at high speeds.

[shinomaster]

How much do you want for them?

Also, Chris Boardman tested the Bontrager race Xlights as more aero than the Mavic Cosmics.

[stevep]

I agree but I do feel (subjectively) that my tt bike with the trimmings is worth a mph or 2 in the 25-29 mph zone. And it goes 42-43 down a local hill I can down coast on a regular bike at 39.

yeah but christophe,
on the descent you would be way far out on the curve going 40mph.
aero certainly is huge at speed...
point is, i wanna see the curve and what it does between 23-30mph...
which are the speeds in fairly normal use during races

my guess is neglibible at 23 and incresing to significant at 30 but not a straight line...
a distinct curve

[chrisroph]

yeah but christophe,
on the descent you would be way far out on the curve going 40mph.
aero certainly is huge at speed...
point is, i wanna see the curve and what it does between 23-30mph...
which are the speeds in fairly normal use during races

my guess is neglibible at 23 and incresing to significant at 30 but not a straight line...
a distinct curve

Agreed on all points.

[chrisroph]

How much do you want for them?

Also, Chris Boardman tested the Bontrager race Xlights as more aero than the Mavic Cosmics.

make offer.

boardman who?

[shinomaster]

yeah but christophe,
on the descent you would be way far out on the curve going 40mph.
aero certainly is huge at speed...
point is, i wanna see the curve and what it does between 23-30mph...
which are the speeds in fairly normal use during races

my guess is neglibible at 23 and incresing to significant at 30 but not a straight line...
a distinct curve

SteveP. Will the wheels make you tricycle go faster? Did you ever get your Zank?

[shinomaster]

make offer.

boardman who?


http://www.lunt.demon.co.uk/boardman.htm

[stevep]

SteveP. Will the wheels make you tricycle go faster? Did you ever get your Zank?

got it.
first ride today.
nice bike

[chrisroph]

got it.
first ride today.
nice bike


lucky guy.

[mflaherty37]

Meaningless numbers. Any real test would at least indicate the speed through various yaw rates, and really the whole system and the ambient conditions is critical. And if it is wind tunnel data it doesn't apply to pack riding. It is hard to find go wheel data, even Zipps website is sugar coated.

[shinomaster]

lucky guy.


You gonna ditch your Sachs for A Zank?

[davids]

got it.
first ride today.
nice bike
Let me guess... Is it blue?

[DfCas]

Cartridge bearing hubs have varying amounts of seal drag when new:some break in and become very low in seal/bearing drag,some remain somewhat high.

Balls bearing hubs generally have less drag when new. I doubt that variable was considered in the tests.

[TimD]

... my guess is neglibible at 23 and incresing to significant at 30 but not a straight line... a distinct curve

Aero drag is a cubic function.

[RPS]

Aero drag is a cubic function.That is correct in terms of power, but not when measured as a force; which is the more normal way to measure and report drag.
Drag force goes up by approximately the square of relative speed (approximately because the coefficient of drag is not always constant).

[RPS]

my guess is neglibible at 23 and incresing to significant at 30 but not a straight line...
a distinct curve
If improvement is looked at on an absolute basis you are correct -- 2 or 3 watts of power savings is a low percentage of the total.

However, since rolling resistance is relatively low at any speed above 20 MPH (i.e. -- 20% or less for most) then if follows that any drag savings the wheels may provide at speed will be approximately the same when expressed as a percentage of the total drag. I expect the percent improvement to be relatively close at 23 or 30 MPH.

[saab2000]

so ... i should keep my nucleons?

Without a doubt.

[Cinci Jim]

Gracious, they were going fast.

I was thinking the same thing... I looked at wiki and the speed of sound is 1238 km/h or 20.6 kpm. Damn, they were smokin' at > mach 2.5!