Since Chris King is one of the slowest companies in the world in terms of brining new products to market I'm assuming there are no immediate plans on the part of CK to embrace the ceramic bearing revoltion that seems to be upon us. But it got me thinking, could I replace the bearings in my CK Classics to a generic ceramic bearing?

The achiles heal of these hubs is their drag, but if I replaced the stock CK cartridge bearings coukld I get around this? Only problem is I'm not sure of the dimensions of the properitary in-house CK bearings? Anyone know - and more importantly has anyone tried this?

RD

ceramicspeed will make any dimensions you want.

-Eric

Since Chris King is one of the slowest companies in the world in terms of brining new products to market I'm assuming there are no immediate plans on the part of CK to embrace the ceramic bearing revoltion that seems to be upon us. But it got me thinking, could I replace the bearings in my CK Classics to a generic ceramic bearing?

The achiles heal of these hubs is their drag, but if I replaced the stock CK cartridge bearings coukld I get around this? Only problem is I'm not sure of the dimensions of the properitary in-house CK bearings? Anyone know - and more importantly has anyone tried this?

RD

"ceramic bearing revolution"???


The only advantage is their ability to suck your wallet dry for negligible gain. Perhaps that's why CK hasn't forced them upon us?

Okay, maybe revolution is a little of an exageration, but the benefits of ceramic in terms of both maintenance and performance are pretty great.

The average decrease in rolling resistance vs. steel bearings is about 4%. On a 17lb bike that's like like losing 300grams....not bad for $100.

Thanks Ergot - I sent an email along to ceramicspeed

Okay, maybe revolution is a little of an exageration, but the benefits of ceramic in terms of both maintenance and performance are pretty great.

The average decrease in rolling resistance vs. steel bearings is about 4%. On a 17lb bike that's like like losing 300grams....not bad for $100.

//////////thread drift/////////


Don't know who you're quoting/getting your numbers from, but I'll refer to the Bicycle Science book which comes to the conclusion after a good deal of number crunching that they're a waste of money (for many reasons).

To be honest I read an article in Bike Magazine and have read some info on the web - probably pretty biased materials...

Maybe I've been sucked in??

Most riders vastly overestimate hub bearing friction. Frictional losses from standard hub bearings are tiny. Depending on quality and type of bearing, front wheel hub losses run from 0.006-0.015 Nm, rear wheel hub losses from 0.011-0.025 Nm. At about 28 mph, you need only from 0.06 to 0.14 Watt to overcome front wheel hub losses, and from 0.11 to 0.23 Watt to overcome rear wheel hub losses. These numbers might not mean much until you compare them with other frictional losses. At that same speed, frictional losses from the chain rob you from 3 to 6 Watt, while tire rolling resistance robs you from 45 to 60 Watt.

There's no doubt that ceramic bearings reduce frictional losses. But when you look at the numbers, the amount gained is so tiny that it completely disappears in the noise of all the other frictional losses. Installing ceramics is sort of like waxing an SUV to improve fuel mileage.

Most riders vastly overestimate hub bearing friction. Frictional losses from standard hub bearings are tiny. Depending on quality and type of bearing, front wheel hub losses run from 0.006-0.015 Nm, rear wheel hub losses from 0.011-0.025 Nm. At about 28 mph, you need only from 0.06 to 0.14 Watt to overcome front wheel hub losses, and from 0.11 to 0.23 Watt to overcome rear wheel hub losses. These numbers might not mean much until you compare them with other frictional losses. At that same speed, frictional losses from the chain rob you from 3 to 6 Watt, while tire rolling resistance robs you from 45 to 60 Watt.

There's no doubt that ceramic bearings reduce frictional losses. But when you look at the numbers, the amount gained is so tiny that it completely disappears in the noise of all the other frictional losses. Installing ceramics is sort of like waxing an SUV to improve fuel mileage.

Yeah but that could turn your 5000 mile year into 5000.25 miles next year.

Yeah but that could turn your 5000 mile year into 5000.25 miles next year.
Just think how much less food you would have to eat to keep from gaining weight, because of the energy savings

Maybe I've been sucked in??

Ya think? :)

Since Chris King is one of the slowest companies in the world in terms of brining new products to market I'm assuming there are no immediate plans on the part of CK to embrace the ceramic bearing revoltion that seems to be upon us. But it got me thinking, could I replace the bearings in my CK Classics to a generic ceramic bearing?

The achiles heal of these hubs is their drag, but if I replaced the stock CK cartridge bearings coukld I get around this? Only problem is I'm not sure of the dimensions of the properitary in-house CK bearings? Anyone know - and more importantly has anyone tried this?

RD


The drag in Kings is from the seals on the HUB not the seals on the cartridge bearings. SO...if you want to reduce seal drag to zero, remove ALL the seals on the hub. Easy, quick, and simple. Plus, you'll knwo when to service the hub, simply wait for them to come to a grinding halt.



The worst thing about this ceramic bearing marketing is that they fail to mention that the inner and outer RACES aren't treated in the same way the balls are.

Buy a nice case of wine with the money and forget about the ceramic bearings....

The drag in Kings is from the seals on the HUB not the seals on the cartridge bearings. SO...if you want to reduce seal drag to zero, remove ALL the seals on the hub. Easy, quick, and simple. Plus, you'll know when to service the hub, simply wait for them to come to a grinding halt.



The worst thing about this ceramic bearing marketing is that they fail to mention that the inner and outer RACES aren't treated in the same way the balls are.

Not only is it the seals that is causing the drag it is the lack of a center support bearing!

Not only is it the seals that is causing the drag it is the lack of a center support bearing!
I do not understand the term, Center Support bearing, at least the application here in hubs. I do not remember a center support bearing in Dura-Ace hubs, maybe I missed something. Or was that a big bug flying over my head??
Thanks for helping a fella out in learning more.