replaced BB - now c...
 

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[Closed] replaced BB - now chainline isnt right?

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Hello,

I've been helping a neighbour with his his bike.. he has a v basic bike from the equivalent of halfords here...

He has a square taper BB which was goosed..he replaced it with a shimano cartridge unit (same dimensions exatcly) and now the chainline is shot..

i dont understand i must admit - never had that happen..?

What do you think?


 
Posted : 26/08/2018 8:23 am
Posts: 9
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How did you measure the BB, that was "goosed"?

The length of the spindle/axle doesn't always equate to the stated size of a BB. Found this with Shimano BB's.


 
Posted : 26/08/2018 9:09 am
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there are also at least 2 "standards" for the dimensions of the taper, maybe he/you got unlucky if the previous one wasn't shimano


 
Posted : 26/08/2018 9:20 am
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Not an "E" type is it?


 
Posted : 26/08/2018 9:39 am
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If the old BB/crank was ISO and replaced with a JIS of similar dimensions, the 'fatter' taper of the JIS BB would push the crank/chainline 4.5mm out.


 
Posted : 26/08/2018 9:47 am
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ah ok, many variables.

I measured the length of the spindle on the one that was going out, as i have always done.. then measured the frame and thought it'd be good...

its not an old bike, just a cheapo one.

Going to have a remesure and see.


 
Posted : 26/08/2018 2:05 pm
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I measured the length of the spindle on the one that was going out

The size should be marked on the old BB.


 
Posted : 26/08/2018 2:51 pm
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yes thanks it was but we measured just incase! Its a cheapo bike and was semi printed on the bb.. but not v clear.

in all my years of mtbing and biking in general ive never had this issue..

sorted it now. all is good. ta singletrack


 
Posted : 26/08/2018 7:00 pm
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what was wrong ?


 
Posted : 26/08/2018 7:16 pm

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