ceramic wheel bearings
Posted: 9 Oct 2012, 10:57am
does anyone have any experience of same?
do they offer any advantages in being more hard wearing? or another example of 'fixing' a problem that doesn't really exist?
Re: ceramic wheel bearings
Posted: 9 Oct 2012, 11:20am
there are some theoretical advantages to using ceramic bearings, but....
1) the potential gains vs conventional bearings (under otherwise similar circumstances) are very small indeed. Insignificant in fact.
2) there are normally other things that can be done to conventional bearings (at lower cost) that will create similar changes in bicycle bearings.
My view is that if you genuinely have run out of other places to spend money on your bike, and/or you are trying to solve a specific problem that cannot be addressed in any other way, maybe you should think of ceramic bearings. Otherwise it is probably not the best use of any limited resource of time/effort /money you might have to spend on your bike.
Some of the advantages touted for ceramic bearings (in bicycle applications) can be attributed to other things or can be acheived in other ways. For example improved corrosion resistance can be obtained by using stainless steel bearings, and the 'lower bearing drag' -which is tiny anyway- is often attributable to a change of lubricant as much as anything else.
BTW someone once suggested that a single ceramic ball bearing in amongst the others might be a good idea. It may have been a journalist; a journalist certainly repeated it, anyway. Quite what the benefit was meant to be I am not sure...but..this is not a good idea at all. Firstly there is no guarantee that the balls will all be the same diameter (and they should be; e.g. Campagnolo ball bearings are 1 micron tolerance...), and secondly even if they are, the stiffnesses are not the same. This means that the balls cannot share the load as they should do in any event.