While many French-threaded pedals are marked D and G, some are not marked at all. In these cases I simply (carefully) try threading them into a known French-threaded crank arm. If no threads are damaged on the arm or pedals, a French-threaded pedal should thread into a French-threaded crank smoothly using only moderate hand force. After a couple of turns, an English-threaded pedal will tighten up in a French crank. You can thread it all the way in using a wrench, but doing so will damage the threads. I'll bet there are a lot of old French cranks out there with English pedals that were forced in by some teenaged bike shop mechanic who never heard of French threads. Conversely, the English-threaded Stronglight cranks on my 1973 LeJeune actually came with French-threaded Lyotard pedals which I unknowingly rode for some time before replacing them with more expensive pedals. Evidently, the pedals had been tightened enough to prevent them working loose despite the undersized thread. I was lucky, as this combination will usually result in the French pedal moving around enough to damage the crank thread.
Regards,
Jerry Moos
Rick Chasteen a démandé:
>Is it possible to differentiate between French and BSC pedal threads
>visually, sans thread gauge? Can French threaded pedals be
>installed on BSC threaded crankarms and vice versa without great
>force and obvious thread damage to the crankarm?
French thread pedals will be marked "D" and "G" for "droite" (right) and "gauche" (left).
French thread pedals are a bit undersized for standard 9/16" - 20 thread cranks.
French-thread (14 x 1.25) cranks can be retapped to standard size, and many existing cranksets marked that way have already had this done.
Sheldon "Filetage français" Brown
Newtonville, Massachusetts
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