I think I'm going to be able to help Jason, but in the process of checking out my BB parts today, I made an interesting discovery. It appears there may be a sort of "universal" BB lockring. That is, many lockrings will work for both English and French adjustable cups. The French 35 mm cup converts to 1.378 in, only 0.008 inches larger than a 1.370 English cup. That's 0.2 mm, or a fifth of one thread. And ISO i s 1.375 inches, a trivial 0.003 inch or 0.076 mm smaller than French. And the pitch difference of 24 TPI versus 25.4 TPI isn't much either.
Today, I took an NOS Sugino French lockring and threaded it easily on to ev ery English cup I tried it on. An NOS Shimano English lockring wouldn't go all the way onto a Sugino French cup by hand, but probably would have with modest wrench pressure. And a Campy English lockring went all the way on to a Sugino French cup by hand. So it appears that that the diff erence between different brands of the same supposed thread is as great as the difference between French and English thread. So a French lockring w ill probably always go on any English cup, and being only a fifth of a th read larger, it should do a more than adequate job of securing the cup. And a lot of English lockrings will thread onto French cups as well, and if you have a lockring that actually matches the ISO standard, a trivial 0.076 mm smaller than French, it will probably work with absoluately any F rench cup. So while I'm probably going to be able to come up with the French lockring for Jason, he probably could have found an English lock ring in his parts b in that would have worked. Truth is with used lockrings separate from the BB, you probably often can't tell for sure if thay are French or Engl ish, as they will work with either type of cup.
Of course these lockring are not truly universal, since Italian is a full m m larger than French or English or ISO.
BTW, the lockrings I am having trouble finding are the left-hand English on es that are used on sealed bearing BBs that allow chainring adjustment by using adjustable cups on both sides, the right cup obviuosly still being left hand thread . Anyone know a source for these left hand lockrings?
Regards,
Jerry Moos
Big Spring, Texas, UAS
From: Jason Cloutier <velo59@yahoo.com> Subject: [CR]French BB parts needed To: "Classic Rendezvous" <classicrendezvous@bikelist.org> Date: Saturday, September 20, 2008, 1:24 PM
I'm working on a bike for a friend and the BB needs help. Seems that his local bike shop mechanics are too young to know about French BB threading. They were unable to remove the fixed cup, so they left it in place. The adjusta ble cup was replaced with a BSC cup. The threads in the shell seem to be OK, a s I threaded the fixed cup into the left side and it went in, though with a bit of a struggle.
The bike is a variant of a Peugeot UO-18, branded Helium. It is painted ye llow with black lugs. It has a tab on the left seatstay for a bottle generator along with fold-over tabs under the down tube to hold the generator wire. It als o has the goofy single-side shifter braze-on on the down tube with the wrap-aroun d band for the left (front) shifter that is made to fit around the braze-on.
Does anyone know the connection between the Helium brand and Peugeot?
If you have a set of French BB cups that they are willing to sell, please contact me off list? Something suitable for this level bike would be OK.
I am also looking for an extra French BB lockring. Should be NOS or very n ice condition used. I needed to remove the adjustable cup from a French bike t hat I own in order to determine positively that the Helium had a BSC cup installe d. I seem to have misplaced the lockring. To add insult to injury, I gave a bun ch of scrap metal to a local scrapper and I'm thinking the lockring was in that load of stuff. DOH!
Sincerely,
Jason Cloutier
Pawtucket, Rhode Island, USA