William I am

Hey all. I'm working on updating my 76 peugeot UO-8's drivetrain.

I'm fine with my search for crank arms and chainwheels (except for spindle length), but I'm stuck on whether or not new french-threaded cups are thin-wall or standard wall. This would make the difference between buying a spindle with a distance of 52 (3T/N/SS) or 55 (5) mm between the ridges where the bearings ride.

So... in a nutshell, are new french cups thin-wall or was that a thing that happened briefly and has been done away with?

Cheers

repechage

"Thick walled cups" back in the day were a Campagnolo item, done in concert with their patented reverse rifling to keep dirt out.
Interestingly, all the French threaded Campagnolo bottom brackets I have use the thin cups from before Campagnolo came up with the improved design. For Campagnolo, all Pista bottom brackets use the thin walled cups.
Now, on to other brands...
TA and Stronglight used their own standards, they are close but not as thin as Campagnolo.
Cheaper bottom brackets such as were found standard on a UO8 used a thicker walled cup than the top flight French equipment but not quite as "thick" as the road Campagnolo cups.
Finding tech specs will not be that easy or possible, in general most test to verify, useable measuring is a challenge.

For French threaded bottom brackets today, I think here are the current choices:
An IRD cartridge bottom bracket with French threaded inserts, about $48.
A VeloOrange French bottom bracket $50 to $66
Compass bicycles SKF unit, triple digits
Phil Wood unit, triple digits.

cudak888 

Top-end Stronglight cups are generally on the thin side; close enough to Campag to allow for fudging. Nevertheless, nothing beats a Stronglight spindle, and they're relatively common on eBay.

However, all this is moot if you're looking for a new replacement out of a J&B catalog - and it sounds as if that's what you are up to. If so, you're not going to find any "new" French cups out there for a cup-and-spindle BB. If you must have new, a Velo-Orange French-threaded sealed BB would probably be your best bet - cups, cones, and proper threads all in one. Just remember that you are limited to JIS taper cranks.

-Kurt

JohnDThompson 

"Thin wall" is the typical bottom bracket cup; "thick wall" refers to the Campy Nuovo Record road cups with the rifling in the spindle hole. Unless you're using Nuovo Record road cups, pick your spindle assuming thin cups.

William I am

I found these on amazon and Harris cyclery. https://www.amazon.com/Bottom-Bracket...MC/ref=lh_ni_t https://sheldonbrown.com/harris/frenc...s.html#bottom2 New french thread cups for loose balls. I'm not going with a cartridge bracket for the cost and my ability to maintain an old-school one, not to mention I'd rather keep it somewhat old-school.

Both of these two sources currently offer new french thread BB cups - but neither mention of if they're thin wall or ISO(or JIS?) thickness.

I'm mostly trying to ascertain whether or not these new cups are "thin" wall or not.


The impression I got was that english cups and french cups, aside from the different threading, had the same wall thickness - except for thin-wall cups. With the thin-wall cups, it's necessary to use a spindle with a wider 55mm spacing for the bearing ridges, and that the ISO 5- type spindles would work. The issue is that the same BB shell width of 68mm with thin cups needs a 55mm "B" spacing, while non-thin-wall(ISO?) cups would work with a spindle with 52mm "B" spacing. I'm taking the specifications from https://sheldonbrown.com/bbsize.html#japan and https://sheldonbrown.com/harris/frenc...s.html#bottom2

Cheers


PS It looks like JohnDThompson has the answer I'm looking for, but I wanted to point out that new BB French cups are available and to figure out what the thin vs not-thin standard is.

mparker326

I asked Harris that same question a few months back. They told me the new cups were thick walled.

repustrops

I used the Amazon French bottom bracket set and a 5 series axle also from Amazon to replace the bottom bracket on my Peugeot UE-8. About 1/8" of the adjustable cup sticks out from the lock ring after installation.

William I am

About 1/8 of an inch is about 3mm - the difference between size 5_ and 3_ spindles. The BB cup I have installed right now has 1 thread visible - so nothing sticks out of the lock ring. Sounds like a 3-series would work with little to no extra - which sounds like the Action (brand) cups are not thin-wall.

Sweet! Thanks for the two answers. That's what I was looking for. Should have linked the product and named the brand initially.

Cheers