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While looking for replacement pedals for my old French bike, I've come across products which are labelled as having thread size "M14/125". Does this denote the "traditional French" threading of 14*1.25mm?

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Yes, this does.

Another option is to re-thread the cranks if you take it to the right bike shop, and then install a standard pedal.

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    Easier said then done. Don't forget that one side is threaded right hand threads. The other side is left hand threads. And left hand thread dies aren't cheap. – zipzit Apr 25 '16 at 4:15
  • Which is why you take it to a bike shop, where they will have purchased them, rather than buy it yourself. After they ask you why you aren't just replacing the crankset, they'll probably do it. – Batman Apr 25 '16 at 6:26
  • Most modern bikes are threaded 9/16" x 20 threads per inch (which requires a .5118" to .5156" OD drill) the 14x1.25 requires a .5039" drill so yeah you've got a shot. The only issue is the 14mm thread OD is larger than the .5156" dimension, so it's quite possible to do the re-tap and still not have enough metal in the right place to give you strength. But I'm happy to admit when I'm wrong. I just checked the price on the taps. I was way off base. LH thread tap < $20 on Ebay. RH tap should be around $10. So a bike shop or buy the taps yourself and go to a machine shop locally. – zipzit Apr 25 '16 at 6:53
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    The OD issue can be solved with drilling to oversize and installing a helicoil. This also keeps the different thread densities from interfering. – ojs Apr 25 '16 at 19:08
  • @OJS, right you are, but I have no clue where you'd go to find those inserts and the taps required for them. 9/16 x 20 threads per inch is not a very common size. Right hand thread is doable, left hand thread, not so easily. It might be easier to attempt the simple drilled conversion from M14x1.25 to 9/16-20, see if that works. If not, Tig weld up the hole, bring it to a machine shop and cut 9/16-20 again. – zipzit Apr 25 '16 at 23:54

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