BB shell threads

[3narf]

CR list British, English and Italian BBs.

Is there really a difference between British and English?

I can't remember what I bought last time, but I just fitted an old one into a frame I recently acquired (to check chain line); it was tight but went in OK. Does that mean it's the correct one, or would the wrong one fit anyway? It's academic as I don't know what thread the old one is.

I would have assumed it's British, but now maybe I'm thinking it could be English...

FYI it came out of a '70s/'80s Falcon and went into a '90s Lee Cooper.

 

[3narf]

Sheldon doesn't list anything called an 'English' BB thread so I guess it's the same as British.

 

[Levo-Lon]

It may date back to imperial.
But I've only ever seen the English and Italian.

I'm sure someone will have a answer

 

[si_c]

BSA = British = English = ISO

It's pretty much the defacto threaded standard, and used everywhere on bikes made after about the mid 1980s, with the exception of some Italian made bikes.

You may see mention of a Raleigh BB (26tpi instead of 24tpi), which is not the same, but only on Raleigh frames, and not so common after the 1970s. Italian (24tpi, but a wider shell and longer threads) and French (25.4tpi with both cups threading the same way) are the remaining two options, although there is Swiss (same as french, but with reverse threaded cups on drive side) , but it's not common.

 

[3narf]

Great, thanks!