Bottom bracket help...

[rich p]

... I have a Campag square taper type BB with these numbers printed on it...

... 1,370 x 24 which indicates English

and 70mm which seems to indicate Italian

help!

 

[festival]

Your right, the first figures indicate English threaded bb shell and the 70mm indicates the size of the bb shell.
So what do you want help with?

 

[TheDoctor]

IIRC it is possible to fit an English BB into one side of an Italian threaded frame - it's the fixed cup side that needs an Italian one because it's threaded t'other way round.
Maybe that's been done at some point?

 

[rich p]

Your right, the first figures indicate English threaded bb shell and the 70mm indicates the size of the bb shell.
So what do you want help with?

Because according to this wiki chart - halfway down the page
http://en.wikipedia.org/wiki/Bottom_bracket
the English thread should be either 68 or 73 and the Italian is 70.

IIRC it is possible to fit an English BB into one side of an Italian threaded frame - it's the fixed cup side that needs an Italian one because it's threaded t'other way round.
Maybe that's been done at some point?

The threads seem to be English in that one goes the 'wrong' way and I'm pretty sure it hasn't been bodged or altered.

 

[PpPete]

Have you tried installing it in a frame that you know is english threaded / 68 mm shell?

 

[rich p]

Have you tried installing it in a frame that you know is english threaded / 68 mm shell?

No, good idea though! It would mean removing another BB on another bike. I may pop in to the lbs on my way to town today.

 

[Brommyboy]

French, Italian and British shells are all different! The thread pitch differs, as does the diameter and the LH or RH thread! If yours is Italian, then that is what you will need. As it is only the cups which differ, a good shop can supply these.

 

[accountantpete]

The previous installer has slightly bodged things.

You have English cups 1,370 x 24F and an Italian axle which presumably reads 70-SS or something similar.

I'd start back at the beginning and measure your BB shell.

 

[rich p]

The previous installer has slightly bodged things.

You have English cups 1,370 x 24F and an Italian axle which presumably reads 70-SS or something similar.

I'd start back at the beginning and measure your BB shell.

Thanks Pete but the 1.370 x 24 and 70 are all stamped onto the outside face of both cups.

 

[accountantpete]

Thanks Pete but the 1.370 x 24 and 70 are all stamped onto the outside face of both cups.

I don't know of any BB's that had the BB shell length marked on the cups - so it is a bit of a mystery.

A quick google reveals that a few bikes did have english thread/Italian 70mm width - mainly decent bikes made with a super stiff BB in order to avoid flex in that area.

 

[rich p]

I don't know of any BB's that had the BB shell length marked on the cups - so it is a bit of a mystery.

A quick google reveals that a few bikes did have english thread/Italian 70mm width - mainly decent bikes made with a super stiff BB in order to avoid flex in that area.

Hmm, the plot thickens and I'm thick!!
Looking more closely at the stamped lettering it appears that it says 70N or something - would that be torque and nothing to do with shell width?

 

[accountantpete]

I'm useless with torque numbers Rich - as originally advised you need to get the BB off and get a ruler out and see what is going on!

 

[festival]

50n-m would be maximum for tightening a bottom bkt, me thinks.

 

[rich p]

Okay, panic over. Stand at ease men.

On closer inspection, (I know, I know) the 70 is stamped with 70Nm (albeit very faintly). So it's the Newton/metres torque not mm!
Thanks for listening

 

[accountantpete]

May I suggest