Well, the French 1.25 mm pitch is very close to the 20 TPI of English pedals, which works out to about 1.27 mm pitch. That is why French pedals thread into English cranks, but are just a little loose due to the slightly smaller thread diameter. What I suspect TA has done is split the difference by making the actual thread diameter perhaps 14.15 mm versus the nominal 14 mm. This would be a little looser in the crank than a true 9/16 pedal, but would work fine as long as one took care to keep the pedal properly tightened so it didn't work loose and damage crank threads. The greater concern might be putting these into a French crank, which might in essence tap out the crank slightly, making true French pedals looser in the future. Maybe TA figures that French thread is so rare now that owners of French cranks don't have many options and would consider this an acceptable compromise.
Regards,
Jerry Moos
Houston, TX
<classicrendezvous@bikelist.org> Sent: Saturday, February 15, 2003 3:39 PM Subject: Re: [CR]TA Pedal Thread
> Hi, allI can comment on is that the standard pedal thread is 9/16 BSF,
> that is british standard fine, it is finer that BSC ( british standard
> coarse ) and coarser than UNF ( unified national fine ), 9/16" works out
> at 14.28mm, so its a little bigger. I have never had any pedals other
> than the normal so can't really comment on what can be done, but I would
> think that the 2 could not be mixed, I know whan I fitted my campagnolo
> pedals to my Galli cranks I needed to run a tap down the thread to get it
> to fit, a proper pedal tap has a taper on it to allow for a slight
> variation on pedal spindle threads, just my 5 cents worth, it maybe
> helpful to somebody one day........regards wayne davidson invercargill
> NZ......