very good posting, madcow!
and something to add: maybe one can save something with an fsa ceramic bb(wich, as you said, is absolutely not proven), but this saving would probably just compensate the lost power because of those flexy cranks...

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Scott CR1 6.67 kg

This guy has been posting ceramic bearings on ebay as replacements for Dura Ace, Hollowgram SI, FSA, etc.

http://cgi.ebay.com/Ceramic-bearings-Sh ... dZViewItem

Remove all seals.
Done for a short distance special event in low-dust conditions only.
After removing the seals, it doesn't take long for dust to increase bearing drag higher than with seals.
Bearings (including cup and cone for loose bearings) must be replaced frequently.

'Polishing' or 'lapping' the bearings. You put a polishing compound on a set of new balls, cups and cones and spin then. Obviously, it is only for loose-bearing type of bearings. The instructions warned to be patient and turn the bearings slowly. It is easy to polish too much. After the bearing track is polished correctly, you remove and throw away the polishing bearings and clean the cups and cones super-clean. You then install new bearings with the normal grease and enjoy. It can be done to the bb, hubs and freewheel. It claims to also increase bearing life.

I did this once, it took a loooong time.

This is from an article in a cycling magazine about 25 yrs ago. I don't remember all the details. I can take 2 hrs looking it up if you like.

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Equality for Cranks.

I have good luck with Boca.

www.bocabearings.com

They have searchable inventory set up by manufacturer. You can find FSA, Shimano, or Campy. Then see what they have avaliable.

Starnut

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"Don't pedal harder, pedal faster!"
Q-FACTOR IS A RED HERRING

BB30.COM

BocaBearings Bicycle Cross Reference Guide Categories Alphabetical list of mfg.
Sealed bearings for almost every mfg there is. Steel, ceramic and full ceramic ($600 each!).

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Equality for Cranks.

anyone know or have tried installing the ceramic bearings from FSA megoexo on a clavicula crankset?

Does anybody have the actual report of this? Because I don't believe it. Bearing friction on bikes has always been considered to be *very* small.

This is from Inside Tri: http://www.insidetri.com/train/bike/art ... 960.1.html

Typical coefficient of friction for a ball bearing is about mu=1.5e-3
(for example, http://www.ntnamerica.com/Engineering/P ... ictemp.pdf)
Power dissipated in one bearing is
P1 = mu * (m/2) * g * V_bearing where m is mass of rider+bike V_bearing is linear speed the bearing rotates at.
P_bearingloss = 2*P1 total power lost in two wheels
V_bearing = V_bike * d/D d = bearing race diameter = wheel diameter
P_bearingloss = mu * mg * d/D * V_bike
P_bearingloss = C_bearingloss * mg * V_bike where C_bearingloss = mu * d/D, can be compared to C_rolling resistance of tires
For a bearing race diameter of 20 mm and wheel diameter of 668 mm (700x23) C_bearingloss = 4.5e-5
for comparison, C_rolling resistance is supposed to be 4e-3 for smooth pavement (e.g. from www.analyticcycling.com), or 100x higher.

For a rider+bike of 75 kg traveling at 10 m/s, I get that the power dissipated in wheel bearings is 0.33 watts.

can you give us some SN of ceramic bearing for Record so I test the upgrade and let you know???

Madcow:

Fine posting! I like your opinion in that way.....

Westbank:

Look at www.ceramicspeed.com

To all:
The drag of the bearings and other mechanical movement on our bikes don't matter that much. See the attached graphic.

The biggest problem is the front of the rider cutting thru the air. That is consuming the most watts and as you are going faster it gets worse. So mind your position and you can make a lot more profit then the tiny watts you win by using ceramic bearings. But is everything is perfect then you might try the ceramic bearings at the next Olympics (because there it would matter).

I just bought them to try. I am happy with them but comparing to what you will be able to improve ...... The costs are huge!

Aerodynamic spokes and tuning your position are a lot cheaper and give you far more result. But ceramic bearings are COOL!

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My bike is Italian so it is Nervosa and of course has Anorexia I like them thin!
GIOS "New" Carbon Ultra 2006 Campa Record+Special parts.
GIOS "New" A90 2008 Campa Record+Special parts. My winter and vacation bike.

That would not be necessary, as you can get a good quality ceramic bearings for the THM's I've put them into half a dozen pairs now. No noticeable difference, except that the seals are even tighter than the originals, but again, tight seals have never bothered me. I don't think it creates a sufficient amount of drag.

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It's not a significant amount of drag, and the amount that bearing drag increases is a linear function, unlike aero drag. The drag from seals is a constant and doesn't increase with speed.

While it doesn't increase with speed part of that drag is not friction but stiction. In essence the effect will decrease as speed increases.

Ciao,

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Being a snob is an expensive hobby.