Ceramic bearings

mitchgixer6

Hi all

I know this has been done to death, and I've been reading up a bit in the subject recently. But thought I'd drag it up here again! :oops: I've never been convinced that they would make a big difference, but having never tried them I'm curious as to how they perform.

I'll be building up a new frame over the winter and am considering putting ceramic bearings in for the BB. I've been reading up in the seals available on certain systems as well, and as far as I can tell the VV seals offer up much less resistance than the standard 2RS.

So are ceramics worth the money? Or should I find some steel bearings with low drag VV seals?

bbrap

Unless the BB bearings are shot I defy anyone to be able to tell the difference between ceramic and standard when riding. May be measurable in the lab but mainly designed to separate the gullible from their cash.

sungod

quality is more important than material, low grade ceramics will be worse than good steel, good ceramics cost a lot, any advantage vs. equivalent grade steel is likely to be small

fwiw ceramicspeed claim that if you use their bb, wheel, jockey wheels, all together, they'll save you 6-9 watts (not sure what the parts they are replacing are)

if you do actually get that saving, it'd be enough to usefully reduce finish time in a tt

whether it's better or worse in terms of seconds per quid than other things you could do is another matter

mitchgixer6

As suspected!

Thanks guys. Think for now I'll stick to steel BB's until I otherwise come in to some extra money!

noodleman

I recently bought some new wheels with ceramic bearings. Just out of curiosity i replaced the bearings in my Reynolds with new ones and carried out my own (unscientific) experiment. I span the standard wheel and timed it until it stopped. 1 minute 48 seconds. The ceramic bearings span for 3 minutes 56 seconds.
How much of an effect this will have in real terms i dont know, but there was a considerable difference in the test.

herzog

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19743285#p19743285]noodleman[/url] wrote:

I recently bought some new wheels with ceramic bearings. Just out of curiosity i replaced the bearings in my Reynolds with new ones and carried out my own (unscientific) experiment. I span the standard wheel and timed it until it stopped. 1 minute 48 seconds. The ceramic bearings span for 3 minutes 56 seconds.
How much of an effect this will have in real terms i dont know, but there was a considerable difference in the test.

None probably - more important is how the bearings are maintained.

sungod

it may be nothing to do with the bearings, could be the seals and/or the type/volume of lube and/or differences in alignment and/or retaining pressure on races and/or preload force

for instance, some ceramics are lubed with oil, whereas steel ones are almost certainly greased, it makes a massive difference in a spin down test

mitchgixer6

I did consider that ceramic bearings will last longer than steel counterparts. But the price difference is just too far off.

For the BB I need its £20 for dura ace or £100 + for quality ceramic equivalent. No brainer really

As for the spin test, how do you make sure you're putting the same force in every time?

noodleman

I did say unscientific.

sungod

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19743609#p19743609]noodleman[/url] wrote:

I did say unscientific.