JackJohn

Hi, I purchased some Campy Record stuff, and upon reception discovered the 9/16 crank came with French 14x1,25 pedals. The seller did not realize, he told me they had been used like that by the previous owner with no problems and that I should do the same. However, I don’t want to mix the two standards, my understanding is that this combination should give loose or bending pedals that will eventually damage threads, although the current French pedals do not seem loose and do not bend.

I therefore did a test with three old and one new pair of matching 9/16 pedals. On 4 occasions I had to push a little with a wrench, mostly towards the end but once also at the beginning, of course not pushing much but still a little. Otherwise I could go through by hand or gently with a wrench. In 3 cases when I had to push a bit, some very tiny fibers of alloy came out of the threads. Ultimately, after some back and forth, all four pairs of pedals could screw to the end and I never had to use excessive force. A visual analysis does not show any particular problem, but mine is not a trained eye.

Hence the question: as I don’t know how long the unmatched combination has been used in the past, I just want to make sure that the previous wrong French pedals did not damage threads and that appropriate 9/16 pedals can still be used. Is that possible? Did someone experience this situation? Is there any other test I should perform to be sure before deciding whether to ask for returning the product or not?
Many thanks!

jiangshi

Run a tap through the cranks, then see. I have tapped French to English, NP. Not sure about the opposite, but the tap will tell you.

noobinsf 

It's also typical to run a tap through a crank's threads to clean them when you buy used, since those threads can get nasty after decades of use. If you have no problem threading the pedals in, and they do not feel loose when fully threaded in, then I would think you're good to go.

The shavings you saw may have been the result of clean pedal threads against embedded crank grime, so there may have been a tiny bit of material loss.

merziac

I would encourage you not to use taps, they are too sharp and can take material off that doesn't need to come off.

If you must a chaser might help but if the pedals can be threaded all the way on, I would apply anti-seize or grease, thread on and off a few times, clean threads and leave a trace of lube and call it a day as long as they can be tightened properly.

JackJohn

Unfortunately the opposite is not possible…
Ok I see, thanks, I’m partial to not using a tap (for now), I’ve read enough stories ending up removing material as merziac said. Otherwise I don’t have a chaser but can try a metallic brush, threads look quite clean anyway. I understand that for you as long as pedals thread in and tighten it’s ok, fine then, that seems the case! It just puzzles me: everything I read on this odd combination (not much out there on the net) points to certain threads damage even after a few miles, so either the previous owner did not really use it (which contradicts what the seller said), either I’m missing something, either I’m lookin for a problem that does not exist
Any witnessing from those who experienced this French oddity more than appreciated.

noobinsf 

I meant to ask — are you certain the pedals that came with the crank were French threaded? I have heard of 9/16 pedals produced by French makers being marked “D” and “G,” and that it’s not necessarily definitive if that is the only clue. It could be that the previous owner had 9/16 pedals in a 9/16 crank, and so there may have been no mismatch to begin with.

It has been a long time since I threaded French thread pedals into an English thread crank, but I think I recall a perceptible jiggle when the two were together.

JackJohn

fortunately standards are engraved into these Campy parts, so yes, I’m sure, on top of that I tried the pedals on a French crank, no doubt. That little jiggle you felt is the one potentially damaging crank threads…

repechage

9/16" pedals will bind going into a French threaded crank.
I bought a bike so afflicted. They were engaged about 60%.
French pedals into a 9/16" crank will fit loose to a point then bind up
I would attempt to install correct threaded pedals that are fully cleaned and into the arms fully cleaned with oil and observe.
If they bind up, then clearing with a good quality 9/16" tap should do the trick, you might consider starting the tap from the back side of the arm.

merziac

It very much seems these have been retapped already or something, I agree that it doesn't make sense and I would proceed with caution, make sure they are tight and monitor closely for loosening or other anomalies. If any doubt about being tight enough I would use loctite or super glue to make sure.

You can make chasers out of old pedal spindles as I did with these, they are what I use to rethread cranks from french to 9/16ths and to clean threads when they are fussy.
Also have a french set I made for a PX10 Stronglight crank that had 9/16's forced way in that I restored to french for some Campy pedals that I swapped to french spindles to keep original.

BB was the same with bsa cups forced half way in that I was able to straighten out too, dust cap/crank puller threads had to be rework as well, all good now.

dddd

Of course there is "damage", but I would just torque in the proper pedals to 20 ft-lbs or so and call it good.
Shimano spec's a much higher torque level than that, I'm light so I use a good bit less than their recommended 28(??) ft-lbs.

The metric pedals didn't strip it so the proper ones won't either.

JackJohn

Thanks, in this case incorrect French pedals strangely did not bind, but when installing correct threaded pedals they did not bind either
Yes I will proceed with caution, ok for possible loctite if needed, never had to before and thought would conflict with grease…
mmm, still have to figure out how to make those chasers
And you got back to use some crank French threads after 9/16 were forced in? Interesting, didn’t know it was possible….
Ok, “damaged” but not stripped seems good to me

As a conclusion I think after this I can call it good then, potential damage seems manageable, correct pedals screw in to the end (with some effort but without bending) and some solutions are available. As long as the crank is not irremediably damaged and unusable that is fine for me and will not return it to the seller.
Thanks all!

p.s.: just need another project to use those campy French pedals now

merziac

Made some french chasers and was very careful, chaser cuts can be made with a small triangle file or dremel/small die grinder with mini cut of wheels.

Harbor Frieght pencil grinder

JackJohn

Great, thanks!

merziac

Anytime, the pedal threads I fixed were only about 25% screwed at the beginning, but so screwed I had to cut the pedals off the spindles and vise grip them out then chased them from the back side which is common practice chasing, rethreading, etc.

Done carefully, chasing with chasers reforms the threads without actually removing any material.

Again, if yours are just a bit, even quite a bit tight, I would leave them alone and use anti-seize, tighten properly and monitor closely for the time being.

JackJohn

Excellent

JackJohn

Just talked to the seller, a former mechanic and a nice guy, he said back in the days when 9/16 cranks started to be used in France, there still were plenty of french pedals around, so what they used to do was tapping the crank arms with a 14x1,25 tap and then put those french pedals on with no problem whatsoever, even for faster, powerful riders. To him that’s what happened with this crank. Anyone ever saw this? Most likely in the 70s?

grizzly59

If you can put the 9/16 pedals in square and tight, you’re good, you are using the original threads in the crank. Taps and such will just loosen things up. Bin the Fr pedals. Ride the 9/16s, recheck. Threads on pedals should stay tight / tighter as you ride.