Fitting ceramic bearings to a bottom bracket

demc1982 said:

Instead of paying £140 for a FSA megaexo BB is it possible to just buy some ceramic bearings and fit them to my standard megaexo BB?

I don't see why not but i wouldn't be suprised if FSA have designed the two different BB's to accept different external diameter bearings just to ensure they can rip us off.

Any thoughts people?

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Pull the existing bearings measure them up order some new ones...

Enduroseals or Boco bearings...

The bearings are 25 x 37 x 7 or #6805. Another excellent choice would be Token, "Tiramic", ceramic bearings. Token has 440 stainless races but they are TiN coated for additional corrosion resistance.

Enduro is different size 24 x 37 x 7. They use a flat rubber washer as a dust shield instead of the insertable dust cap like most use.

Thanks for the reply. Do you know why there is a 1mm difference in the I/D?

I have done a little research into these bearings and have come across "full ceramic" bearings. They have ceramic races aswell as balls, as oppose to ceramic bearings which just have ceramic balls, but are shockingly expensive.

Do you know if these would just be "overkill" for a mountain bike application or is this what comes in the FSA megaexo ceramic BB hence the high price tag?

I have tried a lot of different ceramic bearings.
If you live and ride in a perfect world with no dirt or water....they spin a little easier...very little.
If you live and ride in the real world....they are a waste of money...and will fail.
But they will all make your wallet incredibly lighter.
I did put Phil woods bearings in FSA cups and they are still spinning fine.

the mayor said:

I have tried a lot of different ceramic bearings.
If you live and ride in a perfect world with no dirt or water....they spin a little easier...very little.
If you live and ride in the real world....they are a waste of money...and will fail.
But they will all make your wallet incredibly lighter.
I did put Phil woods bearings in FSA cups and they are still spinning fine.

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What a crock of ****...

I blow through a Shimano BB bearing in about two months, hybrid ceramic lasts well over a year probably closer to two years...

jeffscott said:

What a crock of ****...

I blow through a Shimano BB bearing in about two months, hybrid ceramic lasts well over a year probably closer to two years...

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Depends on your riding terrain and style. I'm a big guy, but not really a pedal masher, and I've been on a standard Shimano BB70 for...........9 years? Never had an issue.

Shimano XT for me , service them frequently , never have problems .

jeffscott said:

What a crock of ****...

I blow through a Shimano BB bearing in about two months, hybrid ceramic lasts well over a year probably closer to two years...

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Ok...enlighten me. What are you using....and in what conditions?
I have tried several mfgrs bearing....all have galled and or seized in the wet. And this was on the road( they failed after one mutli hour ride in the rain)..and the FSA ceramic was on a cross bike( which was ridden in 2 really wet races).
I have a XT b/b that has been used for 2 years....22 races plus riding...alot of it in the rain.Still spins free.

demc1982 said:

Thanks for the reply. Do you know why there is a 1mm difference in the I/D?

I have done a little research into these bearings and have come across "full ceramic" bearings. They have ceramic races aswell as balls, as oppose to ceramic bearings which just have ceramic balls, but are shockingly expensive.

Do you know if these would just be "overkill" for a mountain bike application or is this what comes in the FSA megaexo ceramic BB hence the high price tag?

Click to expand...

Enduro's bearing is a direct contact with the 24mm spindle where others use the snap in insert which makes up the 1mm on the 25mm i/s. Full ceramic are not durable and are a waste of money for bike application. Full ceramic are best suited for extremely high rpm and temp. environments. FSA are hybrid bearings, just high priced. No matter which material the bearings are made to make them last you need to do periodic maint. The Token Tiramic bearing is warranted against all failures for a period of 2 yrs.

the mayor said:

Ok...enlighten me. What are you using....and in what conditions?
I have tried several mfgrs bearing....all have galled and or seized in the wet. And this was on the road( they failed after one mutli hour ride in the rain)..and the FSA ceramic was on a cross bike( which was ridden in 2 really wet races).
I have a XT b/b that has been used for 2 years....22 races plus riding...alot of it in the rain.Still spins free.

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I have a 2006 XTII bottom bracket, I ride about 7000 km/y half of that is off the pavement, in the Eastern Rockies...

Lots of rivers crossings, dust, snow, salt and mud...

The first Shimano BB bearings were toast in a month...Since then I have used Enduro hybrid ceramic bearings, I get a year to 2 years, out of them...

I now run the Enduro cups as well, the seals fit a little bit better.

Whatever you are doing sure ain;t right.

Kinda on topic here-

Cold stream crossings are the BB killer in my experience.

Alaska, for instance, has these ice cold streams (year round) that are heavy in silt/particulate, BB's would fry within weeks, the best explanation that I could concoct, was that the seals became cold and less pliable (maybe even contracted) and let that cold water get right in.

The cure?

Simple old school square tapers (non sealed), serviced all the time, or an XTR (post M952). Had an XTR BB go 2 years in that stuff.

Since I have zero experience with ceramic BB's I cannot say one way or the other.

can any one please tell me if a ceramic bb9200 will run a k force carbon crank (not light)?

demc1982 said:

can any one please tell me if a ceramic bb9200 will run a k force carbon crank (not light)?

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The bb9200 I just looked up is mountain bike type, k force carbon is a road crank, isn't it? Cups are slightly different between the two types, so not straight out compatible, could compensate with spacers perhaps.

Bikinfoolferlife said:

The bb9200 I just looked up is mountain bike type, k force carbon is a road crank, isn't it? Cups are slightly different between the two types, so not straight out compatible, could compensate with spacers perhaps.

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My k-force crank is for a mountain bike... i just discovered it requires a bb9000
the k-force light mtb crank needs the bb9200
the k-force road bikes require the bb8000 series

non of which are inter changable due to spindle length, cup sizes and for some reason spline shape!

Can be confussing but as always proper research should prevent any **** ups