BMC Bottom Bracket - Italian or English Thread?

[Mile195]

So it's time for a new bottom bracket, but I've had getting on for 11000 miles out of it so it's not done too badly I suppose.

I'm guessing that given the bike is a swiss brand, the BB will probably be of Italian spec (metric) rather than English (Imperial).

However, before I go spending any money on it, does anybody have any different thoughts? Any input greatly appreciated...

 

[jarlrmai]

What are the signs of needing a new BB?

 

[Biker Joe]

What are the signs of needing a new BB?

You can't turn the spindle?
OK, OK. I'll shut up.

 

[RecordAceFromNew]

So it's time for a new bottom bracket, but I've had getting on for 11000 miles out of it so it's not done too badly I suppose.

I'm guessing that given the bike is a swiss brand, the BB will probably be of Italian spec (metric) rather than English (Imperial).

However, before I go spending any money on it, does anybody have any different thoughts? Any input greatly appreciated...

Italian is the only standard that has a 70mm wide shell so is relatively easy to id, but presumably it is possible for a Swiss bike to have French or Swiss BB depending on vintage... See the section on BB threading here.

 

[Proto]

My daughter's SLC01 Pro Machine has and BSA/English threaded BB

 

[Mile195]

It's unlikely to be French - The bike is Shimano 105 throughout, and the bottom brackets only appear to come in English or Italian, although if it weren't for that, it's certainly a good point.

What are the signs of needing a new BB?

If I rotate the crank on the workstand, it makes doesn't turn silently - there's a "shushing" noise - albeit a fairly gentle one. It also doesn't turn quite as freely as I would expect. It's still ridable, but once bearings start to go it's usually only a matter of time before they seize completely.

As far as I know, bottom bracket cartridges are all completely unserviceable hence why I want to buy a new one.

My daughter's SLC01 Pro Machine has and BSA/English threaded BB

Thanks - good shout. I'm on an '09 Streetfire. I would have thought that mine will almost certainly be the same then.

 

[ayceejay]

In my experience this information is a closely guarded secret and the sure way to find out is the information written on the old one.