Hi Richard,
Ouch! ~ Tough call.
Although I know Stronglight (and Speidel) DID make some French threaded cartridge bearing sets by the late '70s / early 80s these are tough to find, and very expensive, and would likely NOT fit a Japanese crankset. I'm afraid that French threaded bottom bracket cups (for the most part) have not been produced for almost 25 years.
HOWEVER, you can still buy a beautiful new Phil Woods cartridge bottom bracket and can specify French threaded lock rings for it - Sheldon Brown has these available at Harris Cyclery.
Unfortunately, it's not a cheap way to go. Figure maybe $100 - PLUS the cost of the pair of the French thread lock rings, PLUS cost of a pair of the Phil's unique splined lock-ring tools - which are similar to Shimano's splined BB socket tools... uh... only different.
And, to use your dust-gathering 600 crankset, Sheldon would probably have to know EXACTLY which model this is, as the spindle length (as with the Japanese specific tapers) for a specific Phil Wood BBs would depend on this.
If you're really wanting to replace the BB anyway, you might just want to consider a Phil Wood BB... AND, a "different" completely new crankset. Perhaps something really Kool, and one best suited to both the bike and to the type of riding you'll be doing on it.
~ Other alternatives would be [and, I'm sorry, but I can't remember now whether you'd initially said that your original BB was totally shot] :
1.) Have your frames BB shell re-threaded to accept a more common BB. It can be done by a competent framebuilder or a top notch bike shop,... BUT, would you really want to mess with this now on a newly re-painted frameset?
2.) Keep the existing BB and see if the Shimano 600 crankset will fit "adequately" on this, for now.
3.) Use the original BB and the original crankset - until the questionable crank finally just busts apart.
4.) If necessary, buy a new "TA" French threaded NON-cartridge set ~ again, from Sheldon.
5.) You can often find NOS vintage French-threaded BBs on eBay, ... or perhaps also from other List Members, as well.
~ [Sorry, I just checked - Thought I actually had spares from Stronglight, TA and/or Campy, but they now all seem to be in use on my own little French herd]
Good Luck!
Bob Hanson (a Motobecane Lover) in Albuquerque NM, USA
Richard Long Wrote:
"... I consulted the Harris section on French bikes and found the truth of the bracket. French!! Now I have a different issue :-( I checked the crank carefully and found a cracked piece inside the bolt hole of a spider. It's about a 3mm rectangle, not that it matters. I'm not really sure how to proceed at this point. I would like to replace the existing standard bearing with a cartridge. Now I have to find that and a crank. Since the crank is already Japanese (SR) I thought I might use a Shimano 600 I have collecting dust. I need help with this one, I just want to ride the bike at this point. I should be back from the painter today or tomorrow."
Sincerely,
Richard Long
Temecula, CA