i have a pair of easton EA90 SLX's on stripping my rear wheel recently i discovered allot of play in the freehub body so i dismantled said body only to discover that the inside bearings had disintegrated and the outside bearings also had broken balls in. the cheaper option was to replace the bearings with standard steel ones at £8 each from easton rather than their ceramic equivalent at £25 each!
i have searched on line for cheaper steel bearings 15x26x7 found some half the price but is the price relevant to quality?
is performance going to be greatly affected?
and more importantly i thought ceramics were the bees knees?
Neil Aldridge aka mountain man
Whoa! I just looked at the price of your wheels before making a recommendation and I am at loss for words.
Normally I would say just replace them with steel ball bearings from a hardware store but . . . those wheels are pricey.
I think I would try and figure out why they "disintegrated" in the first place before moving forward. BTW, hardware store ball bearings are usually around a dollar/euro a piece or less, and should last a long time under normal circumstances.
Steve
Regarding the disintegration of the bearings, did you over torque or someone else over torque the wheel when the hub was last maintained? Although ceramic is harder than steel, its also more brittle, under compression it will "disintegrate" whereas steel bearings would deform. Even a small over torque could lead to much higher wear on the bearings.
More exotic materials used in bikes typically have less tolerances so when using such things, carbon fibre, ceramic bearings etc. It becomes more important to ensure you maintain it correctly, ensure the torque used is correct, materials and processes etc.
i have a sneaking suspicion that the disintegrated ceramic bearings may have been caused when i hit a pot hole about six months ago. i had to replace the rim, i checked the hub bearings and they were fine but i guess its possible that the free hub bearings may have been damaged but as the wheel hub were ok i didn't check.
perhaps one or two were damaged and over time the others followed?
Neil Aldridge aka mountain man
Yes 10-4 to xeroxes post re going to a bearing supply house and getting a set of steel bearings.
I have replaced bearings on my motorcycle that way . Except for the few bearings that are proprietary and special order.
You do have the size, 15X26X7 thats all you need. May be a good idea not to get sealed bearings so you can service (grease) them, if there is a external seal in the hub. Were your bearings pressed in? Can you get the outer races out without heating the hub or a press? You can make a press using a large c-clamp and some sockets. Although with the cost of these wheels it may not be a good idea as your first project. If its a caged bearings with bearings visible ignore the previous info.Photo would be good.
Get West European made bearings or Japanese.
As KC says on the older cone and race bikes you can replace caged bearings with loose bearings.
Did not know there were any hippies left. Ole hippy me. :-)))
Never Give Up!!!
I agree guys, not too crazy about having my coffee cup in my wheels.
Good maintenance to your Bike, can make it like the wheels are, true and smooth!
the ceramic used is not the same as your coffee cup and yes i have sourced some steel ones from a uk supplier at a fraction of the cost, still extremely disappointed, replacing these with steel ones makes the ceramic ones in the hub totally pointless. i will not replace those but wait till i am feeling a bit more flush and buy the ceramics then
Neil Aldridge aka mountain man
Ok I will agree it is a different substance then my coffee cup. Maybe they are as strong as steel?! If one has a wheel with them inside the hub by all means stick with them. If they make bamboo bikes I am sure that bamboo, plastic, or ceramic wheels are the next generation. Not trying to make it sound like they "suck" or anything just I feel that material meant for other purposes should stay that way. Too dam dangerous as what is gonna happen when this happens..... (pictures below). You will noticed these are steel. Yes the steel ones break up too and can cause a lot of damage. I was going to save these pictures for a different post but this one is a good one. What does anyone think that will happen when the ceramics get to this point? I think they will disintegrate into dust and particles. The reason this one failed is because there was lack of new grease in the hub and probably manufacturer failure. Reason why I stress this is because I really would not like to see anyone get hurt.
Good maintenance to your Bike, can make it like the wheels are, true and smooth!
i did not come on here to try and impress anyone i came for advise in case any of you had used ceramic bearings, evidently not. and seeing as you have exhausted your knowledge or not on the subject i will bid you good bye.
thanks
Neil Aldridge aka mountain man
Joining this thread a little late, but I thought as a Mechanical Design Engineering; I could contribute some useful information about ball bearing materials.
Why ceramic? well on bicycles, weight but mostly marketing - I'd say 1% weight, 99% marketing. Ceramic balls are used in high speed (10,000 rpm and up) very high precision applications, with very careful match of thermal expansion coefficients (CTE). They must be properly (and usually very highly) preloaded; and must always be under compression. Impact loading which results in a loss of compression will destroy the ceramic balls almost instantly. Ceramic expands less than steel - and much much less than aluminum with increasing temperature. As alluded to above, they are not very good for low speed applications (all bicycle applications are low speed). If you are professional road racer, and your mechanic adjusts the bearing preload every day based on the expected ambient temperature - they are okay, and may be worth the weight reduction. If not, they will not last very long. The pro does not care, as they will be replaced at least every week.
Steel is great for bearings; 52100 is the most common bearing steel, it is very hard and very tough. Not as hard as ceramic, but much tougher. It will handle shock loads quite well. 52100 needs to be well lubricated to keep out moisture as well as to function properly as a bearing. 52100 will rust. 440C (and some proprietary cousins) is the most common stainless steel bearing material. It has much better corrosion resistance than 52100, but under extreme environments, it too will rust. 440C is not as hard as 52100, and has similar toughness. Steel bearings are more forgiving of the thermal expansion mis-matches than ceramic.
As others have suggested, the bearing should be replaced every time you take them out. Separate balls are very inexpensive, even at the LBS.
For my the products I design, I have used and would use again NMB, NSK and SKF bearings. These are all ball bearing assemblies. For the vast majority of applications (including bicycles), even so called "cheap" Chinese bearings are more than adequate if they are properly lubricated. For non-competitive riding, an automotive wheel bearing grease will keep your bicycle wheel bearings happy for thousands of miles. I suggest solvent (70% isopropyl alcohol is fine) cleaning the balls, raceways, cones, etc, drying then immediately apply the grease to all the metal surfaces inside the bearing system. Use nitrile gloves - your finger oils are bad for bearings.
Nigel
Nigel is spot on as usual, but I'll go further. The time one spends fretting over ceramic bearings, ordering and installing them will actually SLOW your speed, because rather than spending all that time for .001% advantage (no exaggeration) you could have been riding instead. Miles in the saddle trump pretty much everything else.
As for the original problem - it only takes ONE bad bearing to wreak havoc. Once it fractures the rest bear more stress, especially from impact and seizing due to the broken pieces. Judging steel bearings by the OP's experience in preference to that of millions of riders over more than a century is absurd.
!
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