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French BB replacement
#1
Hey,
I am trying to replace the bottom bracket on an unknown model Pugeot circa 1970 because I broke the crankset during removal (rusted through) and the cups/bearings are quite worn from age and rust.

Unfortunately, I don't know much about the bike or the proper terminology but the bottom bracket is 68mm wide, the cups screw on clockwise and the threads look about 1mm apart but I cant tell more than that. The cottered spindle is 145mm end to end, ~55-56mm between the bearing retainers (on the spindle) and the drive side is ~3mm longer than the other.

I was hoping to to use the Velo-Orange Grand Cru but I don't know what axle length will work or if it will work at all. If at all possible, I would prefer an ISO or JIS square taper as well.

Any help is appreciated. Thanks!
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#2
Both cups threaded clockwise means you indeed have a French threaded BB - threading is 35 x 1 mm. Here are some options and other info on French bikes (one of best bike sites on the Internet) http://sheldonbrown.com/harris/french-cranks.html. It's not clear what you broke - can't break an entire crankset. Crank arm, spindle, etc? Finding a cottered spindle with correct dimensions is going to be extremely difficult if even possible. Converting to cotterless may be an option but will cost some $$.
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#3
Hi Mel;

This BB will work:

http://store.velo-orange.com/index.php/grand-cru-bottom-brackets-hollow-axle-alloy-cups-1153.html

The spindle length depends on the crankset you select. More information is required about your plans and budget to offer much of a suggestion.

For example: http://store.velo-orange.com/index.php/components/cranksets/grand-cru-110-fluted-double-crankset-34x48t.html recommends a 118mm axle length - it assumes a 130mm O.L.D. - so you may need to tweak for a different O.L.D. and your preferences. I tend to go a few mm narrow on the BB axle length because I tend to use the big chain ring.
Nigel
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#4
Thanks for sharing the post...
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