Bottom Bracket Diameter - Standard ?

[jimbut]

Hello, I have been asking a number of questions ( all of which have been resolved by the biking fraternity in this forum ) prior to upgrading a 16 year old racing bike. Another query follows. Is the diam. of the BB shell an ISO standard ? ie will a modern chainset BB ( I am prob. going with Camp. Chorus groupset ) install successfully on even a 16 yr old frame ?
The width of my BB shell is 70mm and the diameter is somewhere between 38-40mm ( hard to measure accurately with cranks on ).
Ta for any and all replies.

 

[Landslide]

The diameter should be standard, however the threads may be English thread (right-hand cup is left-hand threaded/left-hand cup is right-hand threaded) or Italian thread (both cups are right-hand threaded).

Or the threads could be French pattern, in which case your "mate" has lumbered you with fixing up an old Peugeot carbosh*te frame.

 

[hubgearfreak]

is the frame not french or italian?

is the width actually 68mm?

then it's probably standard english

http://www.sheldonbrown.com/gloss_bo-z.html#bottom

 

[Steve Austin]

Very likely to be 68mm.

If its 70, then its unusual. very unusual

 

[jimbut]

The shell width on my BB is definitely 70mm.
The ( External ) diam. is 40 mm making the internal a few mm less.
The bike is a Raleigh Road Ace. The Sheldon Brown article seems to state British frames WILL have a 68mm BB width .. Not the case with my bike. At any rate, is it unlikely that Campag. BB will thread to my frame ( or can you select different threading options ) ?

 

[Steve Austin]

If its a Raleigh, then it will be 68mm, and have an English thread.

If its 70mm, then i doubt its a Raleigh and it could have an English or Italian thread.

 

[hubgearfreak]

The Sheldon Brown article seems to state British frames WILL have a 68mm BB width .

not if you read it all, or read it properly.

raleigh had a special size (71mm) and with a unique thread so if it is 71mm and not 68 it seems that you're knackered, i'm afraid

 

[hubgearfreak]

if you have no luck, there's always this

 

[jimbut]

OK confession time. Firstly I remeasured BB width ( this time using a good metal rule and not the battered old wooden metre rule I prev. used ! ).
The shell is indeed 68mm. ( I didn`t really have to confess to my idiocy, did I ?? ).
The bike IS a Raleigh ( a Road-Ace circa 1990 ). Second confession, the Sheldon Brown stuff is beyond me. If we assume my frame is standard British threading ( with the right and left cups having a different directional threading ) , am I banjaxed with Italian chainsets ? This would of course mean that all non-Italian frames would be in the same situation ( or would it ? ).

 

[jimbut]

I`ve thought of a better way of asking my question.
Here goes ... Is, for example, the Campag. Chorus Chainset made in 2 variations ? 1 for an Italian frame with its BB threading and 1 for a non-Italian frame with its type of threading ?
Hope this clarifies advice I`m seeking.

 

[mickle]

Many BBs are indeed available in both Italian and English threads, however Italian BBs are becoming increasingly rare as most (possibly all) manufacturers have stopped speccing Italian. And if it's a Raleigh it's English. Guaranteed.

 

[Steve Austin]

its easier now you've confirmed its a Raleigh. you need a a Standard English threaded BB. Any English threaded campag BB will fit fine

 

[jimbut]

Ta for that.

 

[hubgearfreak]

if it's a Raleigh it's English. Guaranteed.

why does sheldon mention a raleigh specific size?

or is that only applicable to 1920s and before, or something?