Distance between BB...
 

[Closed] Distance between BB shell face and centre-line of (single) chainring

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Is there a "standard" distance? On a MTB frame etc etc. I'm guessing there's a lot of variables?


 
Posted : 24/07/2011 11:25 pm
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Its not from the shell face but from the centreline of the frame.

Its called the chainline and it's measured to the middle of the tripple ring on a standard MTB. Usually 47.5mm nowadays.

http://sheldonbrown.com/chainline.html

[img] [/img]


 
Posted : 24/07/2011 11:29 pm
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OK cheers, yeah aware of chainline. OK. So is there a standard distance from the centre of the frame to the BB shell face?


 
Posted : 24/07/2011 11:32 pm
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depends on BB shell size. Two standard sizes 68mm and 73mm.

so for distances you can work it out based on chainline - half shell size.


 
Posted : 24/07/2011 11:34 pm
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73mm. So the BB shell will be central with respect to the frame yeah? So looking at 11mm distance between shell face and chainring.

Ta ๐Ÿ™‚


 
Posted : 24/07/2011 11:38 pm
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So the BB shell will be central with respect to the frame yeah?

unless its SARACIN ๐Ÿ˜‰


 
Posted : 24/07/2011 11:39 pm