what bottom bracket?

[foxyrider]

Okay, this is a multipart question which i'm sure there are peeps out there who can answer.

So the frame is a late 70's steel road frame, 68mm bb shell English thread. I'll be running a vintage SR double chainset, Campag pattern but i've no idea what size BB I need to run, I seem to recall 108 but can anyone confirm?

Secondly it originally had one of the first FAG sealed BB's fitted which I may be able to source NOS but does anyone know when Campag changed over to cartridge BB's? I'm trying to keep it period amap so any indication would help me retain authenticity.

Cheers

[Brucey]

campag SR only ever had a three-piece BB IIRC. Using a FAG BB with that chainset would be something of a travesty IMHO. Or do you mean a sakae ringyo chainset? They made several different models with 144BCD and they all used different BB lengths.

The exact BB length can vary with the year of manufacture too.

cheers

[foxyrider]

The 'new' chainset will be an Sakae/SR Apex which looks very much like the Campag cranks of the era (late 70's). Getting a duplicate of the 3 arm Campy Gran Sport that was originally fitted is beyond reasonable cost! I can obtain Campag BB's in 3 types, 3 piece, recessed cartridge and flat faced cartridge. I want to fit a good quality bit of kit but I want something that matches the late 70's early 80's components.

[Brucey]

IIRC few if any of the SR Apex cranks used the same BB length as a campag chainset. You can work out what length you need easily enough, just use any JIS taper as a mock up and subtract/add accordingly to get the chainline you want. 120mm rings a bell (but NB if so it would be 120mm asymmetric).

Again scraping the bottom of my mental barrel, it is possible that a campag GS BB might work OK.

cheers