Broken pedal on an old french bike

Question

I broke the pedal of an old french bike (Peugeut Mixte 70's). The threading doesn't fit the one in modern pedals.

Now I am wondering if I should insist in finding an old french pedal or if I should rethread the pedal support in order to be able to use modern pedals.

Though, I am a bit scared about rethreading. Can it really be done safely? Is the space between threads the same? Has anyone here done this?

Answer 1

It hasn't been difficult to get french pedals direcly from the French ebay! :-)

Answer 2

Yes, a pedal can be reliably enlarged and retreaded, assuming there is enough metal surrounding the original threaded hole. Most good shops have taps for 1/2" and 9/16" pedals, which are the 2 modern standards.

The older French standard is 14mm with a 1.25mm pitch.

It is possible to tap out 14mm to 9/16" without issue, if you have the tools and a steady hand.

Make sure you use the correct tap for the correct crank arm, as the left arm is reverse threaded.

I hope that is helpful.

Answer 3

To quote Sheldon:

Older French bicycles used a different, smaller diameter where the pedal screws into the crank, 14 mm x 1.25 mm.

The vast majority of French bicycles imported into the U.S. used standard 9/16" x 20 tpi crank threading, but if you find an older bicycle that was bought in France, you may run into this problem. The French-thread cranks can be tapped out to 9/16". This is much easier (and more worth the trouble) with aluminum cranks. Start the taps from the inside of the cranks,so any possible thread damage occurs where it doesn't matter. French pedals will often be marked "G" (Gauche=left) and "D" (Droite=right).