"The 33"-Road Bike Racing - American Classic versus Zipp wheel shootout

I'm curious as to your input on the following:

I just purchased a new set of AC Carbon 58 wheels with the ceramic bearings and Sapim spokes upgrade. I noticed that when the bike is on a repair stand and the front wheel is spun it seems to take forever for the wheel to spin down. I decided to try an experiment and put two bikes side by side on the stand. One bike with the new AC wheels, and the other with a set of Zipp 404 clinchers with standard bearings. When the wheels were spun simultaneously with the same amount of force the Zipp wheel continued spinning about a minute and a half longer than the AC wheel. I would have thought just the opposite would have occurred. Any thoughts on this? Thanks.

As an aside, I am the owner of both wheelsets. The local bike mechanic that I use who also happens to be a wheel builder opines that the AC hubs are superior to those of the Zipp. Assuming that they build comparable hubs, I would have thought that the ceramic bearings would have won a rollout contest. Perhaps there are other factors that I am not considering.

This isn't a shootout. The AC's are like Custer @ Little Bighorn.

Zipps RULE. At any rate they do have a cooler brand name and stickers.

The AC wheels use smaller and lighter bearing, good for weight savings but bad for stiffness and longivity, I would assume that this would have something to do with the drag your refering to.

This isn't a shootout. The AC's are like Custer @ Little Bighorn.

Zipps RULE. At any rate they do have a cooler brand name and stickers.

hahahahaha, oh marketing hype.

That test is valid only if your bike rides around without a person on top. The real test is how the hubs perform under load, and I would suppose that you have neither the knowledge nor equipment to test that.

The AC wheels use smaller and lighter bearing, good for weight savings but bad for stiffness and longivity, I would assume that this would have something to do with the drag your refering to.

Perhaps once the heavier bearings gain momentum, they tend to follow Newton's laws of motion a bit better. Also, the Zipp clincher is considerably heavier than the AC tubular, and perhaps that also would help momentum once established. Although I road race on carbon, I time trial on aluminum, and once you get that sucker going with its Zipp 999 wheelset, there is no stopping that beast!

hahahahaha, oh marketing hype.

No hype, simple observation. Zipps have a cooler name and stickers. We can all agree on that.

I've always been told it doesn't matter until there's weight on them.

I've always been told it doesn't matter until there's weight on them.


Perhaps what I did was totally meaningless then.

I agree about the looks - the Zipps have killer looks, especially mounted on my red and black Guru Geneo - I can't stop looking at that bike!

I'm curious as to your input on the following:

I just purchased a new set of AC Carbon 58 wheels with the ceramic bearings and Sapim spokes upgrade.

...




The new seals in the bearings of the AmClass wheels will cause the wheels to be tighter until you get a few hundred miles in on them--try your test again in about 6 months.

The new seals will cause the wheels to be tighter until you get a few hundred miles in on them--try your test again in about 6 months.

That is probably the answer! The Zipps are new also - just replaced by the factory - but they do have 555 miles of hard riding on them.

Zipps, even the non ceramic bearings, are purported to have very low friction in the bearings. So it's possible the friction loss in the Zipps is less, even without ceramic bearings.

But as mentioned the real test is loaded. This is probably even moreso with Zipps because the bearings are non preloaded.

I'm curious as to your input on the following:

I just purchased a new set of AC Carbon 58 wheels with the ceramic bearings and Sapim spokes upgrade. I noticed that when the bike is on a repair stand and the front wheel is spun it seems to take forever for the wheel to spin down. I decided to try an experiment and put two bikes side by side on the stand. One bike with the new AC wheels, and the other with a set of Zipp 404 clinchers with standard bearings. When the wheels were spun simultaneously with the same amount of force the Zipp wheel continued spinning about a minute and a half longer than the AC wheel. I would have thought just the opposite would have occurred. Any thoughts on this? Thanks.

As an aside, I am the owner of both wheelsets. The local bike mechanic that I use who also happens to be a wheel builder opines that the AC hubs are superior to those of the Zipp. Assuming that they build comparable hubs, I would have thought that the ceramic bearings would have won a rollout contest. Perhaps there are other factors that I am not considering.

are you sure about the same force? my guess would be that you got them to the same speed and then watched them wind down. this would account for the zipp clinchers spinning longer because they will have a higher inertia at the same speed than an ac tubular.

are you sure about the same force? my guess would be that you got them to the same speed and then watched them wind down. this would account for the zipp clinchers spinning longer because they will have a higher inertia at the same speed than an ac tubular.

I did try the "experiment" twice being very careful to apply the same force to each wheel. I did it once by gently spinning both at the same time, and on the second one I spun them both hard simultaneously with the same result. It would be interesting to know who builds the hubs for AC - I didn't know until very recently that Zipp supplies the carbon rims to AC. I discovered that when I inquired as to what was holding up my wheel build at the factory, and was told they were awaiting a shipment of rims from Zipp.

Tape a bunch of weights to the tire on one of the wheels and it will spin forever. Its about rotational inertia. The only way this test could even be semi valid is if both wheels had equal rotational inertia. Hell my bench sander at work will spin for 15 minutes after it's turn off, because its heavy as hell.

Tape a bunch of weights to the tire on one of the wheels and it will spin forever. Its about rotational inertia. The only way this test could even be semi valid is if both wheels had equal rotational inertia. Hell my bench sander at work will spin for 15 minutes after it's turn off, because its heavy as hell.


Maybe I should mount a couple of bench sanders on my machine and get rid of both wheelsets! :D

The AC wheels use smaller and lighter bearing, good for weight savings but bad for stiffness and longivity, I would assume that this would have something to do with the drag your refering to.

Sounds good except you are backwards, zipp uses smaller bearings:
15X24X5 Zipp bearings

17X30X7 American classic bearings

I'm sure both are laterally stiff and vertically compliant.:)

Meh, it's about the motor. A friend of mine just won a pro/1/2 GA Cup race on a set of Aksiums.

Sounds good except you are backwards, zipp uses smaller bearings:
15X24X5 Zipp bearings

17X30X7 American classic bearings

30mm bearings in a front hub? I think you read the wrong spec. 30mm is bottom bracket size.

Meh, it's about the motor. A friend of mine just won a pro/1/2 GA Cup race on a set of Aksiums.


Of course the typical wheel sucker can get by with crap wheels, but if you enjoy winning on breakaways (which I do), you need something that can save you a couple of watts (like a nice deep rimmed wheel ala Zipp 404 or AC Carbon 58). But that's a whole other discussion. We know how important the motor is, and to confirm it gets a bit clicheish at this point. It's like the people at golf tournements who have to bleat the obligatory "get in the hole" on every shot close to the green.

30mm bearings in a front hub? I think you read the wrong spec. 30mm is bottom bracket size.

those are rear hub bearings. Sorry, should have specified.

Of course the typical wheel sucker can get by with crap wheels, but if you enjoy winning on breakaways (which I do), you need something that can save you a couple of watts (like a nice deep rimmed wheel ala Zipp 404 or AC Carbon 58). But that's a whole other discussion. We know how important the motor is, and to confirm it gets a bit clicheish at this point. It's like the people at golf tournmments who have to bleat the obligatory "get in the hole" on every shot close to the green.

Yeah. My buddy with the aksium's was in a 2 man break for 45 minutes and still won the race. I guess he's just a chump.

He used to win cat 3 races on a 1989 trek with downtube shifters and openpros but decided to upgrade to STI the same weekend he became a cat2.

The advantage of ceramics is when there is a load applied. NOT putting the bike in a stand and spinning the wheel.

LOAD is the key for ceramics.

Yeah. My buddy with the aksium's was in a 2 man break for 45 minutes and still won the race. I guess he's just a chump.

He used to win cat 3 races on a 1989 trek with downtube shifters and openpros but decided to upgrade to STI the same weekend he became a cat2.

No, he sounds like a hell of a rider! I know how painful it can be. I was in a two man breakaway last December and everytime I looked at my heart rate monitor, it confirmed the pain - I was running in the 180s. I wound up averaging a higher heart rate in the road race than I did in a time trial competition a couple days previous. The guy would be scary with some real equipment!

American classic uses Taiwan manufactured hubs in many of their wheelsets. I'm not 100% on this particular model.

No, he sounds like a hell of a rider! I know how painful it can be. I was in a two man breakaway last December and everytime I looked at my heart rate monitor, it confirmed the pain - I was running in the 180s. I wound up averaging a higher heart rate in the road race than I did in a time trial competition a couple days previous. The guy would be scary with some real equipment!

It would appear that the only equipment he requires is his motor. He is scary now. Dr.W would smoke me on a Big Wheel. Cool bike schwag is nice, but let's not get carried away. Well, OK, I can can carried away with that on BF, but not you. Try to show a modicum of restraint. Excess blather and hokum is Pcad's dept. Please make a note of it, and keep it in mind when you see the 4th 'Zipps Rule' thread I post in one month.

Two rational observers looking at the same evidence can come to greatly different conclusions.

I hate Zipps. I hate the way they look, and I don't like the black, white and red.

Now, bring on the polished aluminium!

I hate Zipps. I hate the way they look, and I don't like the black, white and red.



Your place in hell is reserved right next to DocRay's. God save you my son.

There aren't enough candles in the entire Our Lady of Dura Achee Chapel for all the Campy Sinners on this Forum.

Tape a bunch of weights to the tire on one of the wheels and it will spin forever. Its about rotational inertia..spot on!


What tyres were on each wheel, if any? The heavier tyre will spin longer.

A wheel with a tyre and tube on it spins for much longer than one without


The advantage of ceramics is when there is a load applied. .HED have found the opposite.

They've found no quantifiable rolling resistance advantage on loaded wheels with ceramic bearings, but did on unloaded wheels

"There was a measurable drag difference between ceramic bearings and steel bearings when we tested unloaded wheels, but the difference was small enough that we could not measure it on a loaded wheel."


http://www.hedcycling.com/wheels/ceramicbearings.php

Yeah. My buddy with the aksium's was in a 2 man break for 45 minutes and still won the race. I guess he's just a chump..well, well, well, :) Aksiums tested way above expections on the "Great Wheel Test" for aerodynamcis and rigidity.


http://www.rouesartisanales.com/article-4934445.html

Sounds good except you are backwards, zipp uses smaller bearings:
15X24X5 Zipp bearings

17X30X7 American classic bearings

I was talking about the front hub, to clarrify.

well, well, well, :) Aksiums tested way above expections on the "Great Wheel Test" for aerodynamcis and rigidity.
http://www.rouesartisanales.com/article-4934445.htmlAccording to this, the Aksiums are only 5 watts less aero that Lightweight Obermayers



..............................."watts absorbed at 50kph"

Zipp 808......................................18.1
Ritchey WCS Carbon....................19.3
HED Hed 3...................................19.7
Vuelta Carbon Pro WR.................20.8
Easton Tempest II Carbon...........21.6
CKT Splendor...............................21.7
Mavic Cosmic Carbone SL.............21.9
Shimano WH-7801 Carbon 50......22.9
Campagnolo Bora G3....................23.0
Rose Aerospoke...........................23.0
Corima Turbospoke ......................23.1
Bntrga Race X Lite Crbn aero........23.4
Fulcrum Racing Speed...................23.7
Gipiemme Carbon 5-5...................24.1
Tune Olympic Gold 2005................24.1
Shimano WH-7801 Carbon............24.4
FRM FL-R 23 SD Aerolight..............24.6
Corima Aero..................................24.7
Lightweight Obermayer................24.8
Xentis Mark 1................................25.0
Citec 3000S Aero..........................25.5
Shimano WH-R560........................26.1
Lightweight Ventoux/Standard.....27.3
Campagnolo Eurus........................27.8
Tune Skyline 2006.........................28.1
FSA RD-600...................................28.7
Mavic Aksium Race........................30.0
Citec 3000S..................................30.6
Ambrosio X-Carbo.........................31.5
Campagnolo Hyperon...................32.1
Mavic Ksyrium ES..........................33.2

Could it be that ceramic bearings are a bunch of marketing hype and BS?

Me thinks so...

^ hmmm, possibly :).... but it's funny that HED still sell them, even though they've found no data to support their benefit

you could do a rolling test, assuming you have similar tires on the two sets of wheels (ideally the same),
find a slight hill, and roll down, see which one you go further on/go faster on. you just have to make sure you maintain the same position on the bike for both runs, or multiple runs and average it out....
....
or you could just keep enjoying your fancy new wheels ;)