possible?
they both have the same internal diameter, so guessing not without great difficulty, but perhaps you knowledgeable folks can give some thoughts.
I think it’s gonna be hard. 1.370" = 34.798 and the French BB cup size is 35mm. That’s 0.2mm of wiggle room. Thread size is close 24tpi vs. 25.4tpi. More importantly the fixed cup side on french right hand threaded (as opposed to the standard reverse threading). I don’t think it’ll work … I’d look for Velo Orange’s threadless bottom bracket if the threads are damaged or one of their French BB’s if the threads are fine and you’re stuck for good BB options.
What’s the issue you’re trying to get around?
turns out that despite information from the frame builder to the contrary (“The frame must be threaded in BSA standard”), the french frame i purchased has a french threaded BB (as you indeed suggested could be the case).
so i can’t fit the cups for the veloce group i’d purchased, and they don’t make french cups. i could use square taper cranks, but i’d rather run the complete matched group.
perhaps it’d be an option to get some italian cups retapped to french? there’s 1mm difference there, and i’m guessing the final wall thickness would be no different to the bsa cups.
Hmm … it all gets tricky. If it were me … Campagnolo 170mm Veloce Compact double 50/34 crank and then guesswork/figure out which of the french thread Velo Orange BB’s would give me the right chainline (as they’re a JIS taper).
Maybe I’m conservative but I’d rather some crank than a stuffed BB shell or stripped threads.
Otherwise the only option you have is to retap the BB shell to italian (from 35mm to 36mm) and from a 25.4mm thread (1mm) to a 24 thread per inch. Depends on the shell, depends on the tools and who’s doing the work. Mightn’t sound like much but that’s a lot of material and it’s pretty easy to get it wrong or worse still stuff it up and end up in no man’s land. Keep in mind that the shell width should be 68mm, whilst an Italian shell width (and BB axle design) is around a 70mm wide shell. It’s gonna be touch and go which is why I’d opt for the “leave as is” option and find something to work.
thanks for link. would definitely be the safest option. the frame came with a nice stronglight bb, sealed bearing & adjustable. should be iso, but i’ll have to confirm this.
might give jesse@bikebar a call about retapping campy cups. if it can be done, i’m pretty confident he can do it. will report back.
I might be out of touch but I’ve never heard of such a thing … cups are aluminium and thus fragile.
I highly doubt this will be doable, but if magic can be wrought, Jesse is the wizard to do it. But even if he can, don’t you want to be riding this bike before 2014?
I would do as Spirito suggests and use a square taper French BB with the last of the square taper Campy cranks. They’re very nice, low Q, and will match quite well with the rest of your group.
spoke with jesse, and he seemed pretty confident he could retap the cup, but there was a big question mark on cost and time. infact he didn’t like the prospects of retapping the bb shell.
seems like i’ll have to acquire a square taper crankset. thanks for help folks!
Given a choice I’d actually prefer the square taper cartridge bottom bracket to the new outboard bearing stuff … seen too many issues with the latter, including very short bearing life. Late model square taper stuff works pretty well.