Bearings - 7- 21-31...
 

[Closed] Bearings - 7- 21-31mm Why cant I find any?

Posts: 6
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I need to replace the bearings in a few BB’s I have but I can find any online

I’ve measured them as 7mm OD 31mm ID 21mm
I need 9 or 12 of these if anyone knows where I can find them.

Any help would be appreciated


 
Posted : 30/05/2013 9:24 am
Posts: 251
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shimano had them made to a special design to prevent exactly what you're trying to do 🙁

BETD and so on sell quality replacements but, tbh, complete new XTR BB's from Germany often come out cheaper.


 
Posted : 30/05/2013 9:26 am
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If they are for HT11 BBs then you need 6805 2RS or 61805 2RS. BUT they are 7mm wide, Shimano use a 6mm wide bespoke version in their cups.
Hope also use a bespoke version, so no aftermarket bearings available.
What cups are you using?


 
Posted : 30/05/2013 9:57 am
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21mm ID? What's that from? Hope is 24mm, Shimano 25mm without tophats.


 
Posted : 30/05/2013 10:16 am
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these are for KCNC titanium ISIS bb's
they take three bearings per BB.
the Bearings don't have any markings on them, nothing at all.


 
Posted : 30/05/2013 10:20 am
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There are some available [url= http://simplybearings.co.uk/shop/advanced_search_result.php?search_in_description=0&keywords=21.5x31x7mm ]HERE[/url] but they have an extra 0.5mm on the internal diameter.

My Control Tech ISIS BB uses the above bearing size, just thinking that maybe yours is the same...


 
Posted : 30/05/2013 11:39 am
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Thanks for the link.
Is thtat price for each bearing ?


 
Posted : 30/05/2013 8:24 pm
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Yessum. It makes you wince when you realise you need three per BB, but if you figure-in that I got over four years out of my last set*, it's not too bad. From new I clean and refill with my own bearing grease before fitting. It's an OCD thing...

* Obviously this will depend on the sealing of your component


 
Posted : 31/05/2013 11:16 am