M950 bb, can you retro fit sealed bearings?

ishaw

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While cleaning an m950 bb the other day, I discovered that the spindle has removable bearing collars/races.

A while ago now I had a klein with the press fit bearings and was looking at options to fit m952 cranks on it. There was a company long gone that made bbs for the job, but no dice then as the company no longer existed.

I don't have the klein anymore, but it got me thinking about whether it would be possible to swap the original bearing set up with sealed bearings.

Anyone tried or got any thoughts on whether this could be possible?
 

FluffyChicken

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Direct replacement I would say no, the bearing are tiny as they are hence the balls for location and axial forces and the needle for the main running to take the load.

Without the cups and using press fit you have more room, but you'll loose race surface and backing width.
If you make the bb shell inner diameter larger...
There's probably a reason they went external for the same size shell or made the shell larger.
And ISIS bb's failed a lot quicker, no matter how many bearing races they put in.
 

ishaw

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Everything you say makes sense, small bearings wearing faster etc. However, the m952 is sealed bearings and has the sane axle diameter and they are pretty bomb proof, plus I'm assuming the bearings sit inside the shell that one cup goes over. Never seen inside one so just speculating. I'm not going to try anything, just thinking out loud.

Another probably silly thought occurred, completely without any measuring or checking, but could a longer axle v1 axle be used with an ht2 bb cup?
 

FluffyChicken

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If it's like the other shimano BBs then the axle is still the bearing race, all they add is the cup being a bearing race too
(or they may even have left the 'cup and outer race' as is with a changed of casing only)
You gain rigidity and not having over or under loaded bearings.

So you don't have that extra bearing race to worry about.
 

FluffyChicken

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HT2, ignoring the bearing races, are they not designed to have one crank arm resting against the cups and then the other clamps resting on the other side, with the splines you can't do that.. Orr add wide spacers. Hum...
 

ishaw

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I was thinking due to some cranks now having modular spindle that they are essentially a traditional crank and bb, just with an external bb. Never owned one but remember thinking it when I've cone across them. Just thoughts and witterings.
 
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