So I inherited an old Velosolex frame, perfect candidate for a conversion. I was originally afraid of the prospective sizing issues, but I managed to get most of it sourced on the cheap. The 25.6 seatpost, the cheapo headset that needed a cup or two switched, even the stem turned out to be a simple 1”. I was really on a role, until I met the bottom bracket. I decided to piece one together, and found a French fixed cup in great shape. I found a generic adjustable cup and lockring, and ordered up some bearings… the issue has been the spindle… I have a pair of Sugino Rd cranks, which take a 103mm bottom bracket. Unfortunately, the only cost efficient matching unit is the Shimano sealed BB, which is English threaded.

-Is there any fat chance in hell of me finding a 103mm spindle, that will fit these cranks?

-Despite the fixed cup side being right-threaded, is it worth jamming the Shimano unit in there and calling it a day?

-Can I re-tap the shell to make it English?

-I have a 111mm Suntour spindle… is there a cheapish crankset that will fit that?


HALP.

You'll have a hell of a time jamming ISO in there with different pitch and, more importantly, opposite thread direction. You could check to see how much a machine shop would charge to fill and tap to ISO (can't just tap, since ISO isn't any wider). Might be worth it if you want a long-haul fix compatible with bb changes in the future.

You might check around at local shops to see if they can order an appropriate spindle or have it in a parts bin. You may need a spindle designed for Italian cups (https://www.sheldonbrown.com/velos.html#bottom). For such a short spindle, I wouldn't be too optimistic. But who knows? And if 103mm is for the chainring mounted on the outside of the spider (I'm sure someone here knows), you could move to the inside of the spider with a longer spindle.

It might be easiest to swap out the crankset and use your 111mm spindle. The only 103 mm spindles I've seen are in Sugino cartridge BB (I didn't realize Shimano went that low). I've always been dodgy about rethreading. I opted for Phil retainer rings for my Raleigh Twenty rather than risk pooching the shell with a rethreading effort.

Yet again, Sheldon to the rescue with his Bottom bracket database that shows compatability of various cranksets and spindle lengths https://www.sheldonbrown.com/bbsize.html

You sure you love this frame...

What I found in my French conversion:
1. You can get new BB from Sugino, TA or Phil Wood - $110-$140 for french threaded, though 103 is not available for TA, if I remember.
2. You can machine the bracket for Italian, but not English. That is slightly more available than French, but seems really arbitrary to do that work just to change the thread direction to another squirrely non-standard.
3. Yellowjersey.org has lots of vintage spindles. Email them with what you are looking for and they can help you source it. It will be around $60 (or more) if my memory serves, and they might even have the adjustable cup for French.

Based on my experience, also make certain that you have the right seatpost and stem before you get started. NOTHING is standard, and it does get tiring. If you want to find more, search for Peugeot and french thread.

Sugino French Thread BB link. Pricy, but best to know going in:

Cheers everyone -- I still think I'm going to get away from this one paying more than I had anticipated.

Either I buckle and buy a set of Superbe or Campy cranks (nothing else seems to take 111mm according to Sheldon), or get the Phil retainer cups (that Sugino 75 wont work because I'll still need to get new cranks). I was so convinced that in scoring the French adjustable cup, that I was home free.



The seat post was the only odd size, everything else has been a walk in the park.

Oh, and be aware that campy and sugino have different size tapers. Campy stuff works on campy spindles.

spindles are available. Don't fret too much.

you can't just buy phil cups. you need a cartridge BB to go in them. Phil or shimano UN72.

i am pretty lucky to have my 70's peugeot come with a seatpost when i bought the frame. i had a cottered pin setup for the bottom bracket in which i took a sawzall to since the cotterpins were impossible to get out. i used the stock french cups and used an italian bottom bracket spindle which i found in a couple weeks on craigslist. you can find italian spindles on ebay as well, though they are pretty hard to come by.

i was going to buy some phil wood cups along with the un72 option, but i saved tons more money by buying just a new spindle.