jo_lacs

I have been slowly putting back together a peugeot bretagne mixte that someone threw out a month ago. Today I noticed this. What do you think?
I was hoping to use some other pedals. I may not have a choice if I decide to stick with these cranks. Could they have just been mislabeled?

JohnDThompson 

What makes you think they're mislabeled?

Troul 

Right pedal on left C-Arm.

jo_lacs

The drive side pedal wouldn't budge. I got the NDS pedal to move a little before I realized the situation. I think that if I force the pedals off, I would end up with a useless crankset. (Sigh.)

epnnf

Looks to me the L pedal is on the R c-arm?

rosefarts

Think of the commitment it took to get those in.

vane171

Maybe R means Right thread, not Right pedal? This looks like something historic, antique, maybe the modern standard doesn't apply. Cranks could be more modern and the letter refers to modern standards... My CArms don't have L/R marking on them, only pedals and those don't have it on the axle, so it definitely refers to Right/Left pedal.

Right pedal should have Left thread, right? And vice versa.

The photo doesn't show which CArm is the DS/NDS

zandoval 

Looks like a Right v/s Left Threading thing again... Always a problem in old French bicycles.... Ha

They look great. I would polish them up and use them...

jo_lacs

Crankycrank

I'm with the others that it's the French way of being different. R=right hand threads, etc. Just remove them normally.

jo_lacs

I know, right?

vane171

I have this bike (2007 make, with pedals new last year) around with pedals only on so they don't get lost and checked and DS pedal is marked R (not on the pedal axle but its body) and it has normal Right handed thread. I always thought that the idea behind the different threads on pedals was that they don't unscrew if the bearings get stiff.

But as it is, if the pedal bearings got stiff, the pedaling action would unscrew them. Now I don't know anymore why the bother with the opposite threading on the two sides.

jo_lacs

Meh. It could be worse. It - was - after all, a freebie.

andrewclaus

The theory has to do with the movement of the ball bearings on the pedal spindle. It's opposite the pedal rotation.

HillRider

No, the right (drive side) pedal should have right-hand threads. The left (nds) pedal should be left-hand threaded.

Geepig

Well, you could do worse that get a magnifying glass to inspect the threads on the pedals and cranks on the non-pedal sides of the cranks.

CliffordK

What are the chances your pedals will be 14mm x 1.25mm threads?

Apparently possible to retap to standard 9/16.

easyupbug 

Cross threading is one thing but what is suggested is effectively impossible. Soak with Kroil/JB Blaster/etc. and get them off. That said, I am often amazed by what well meaning folks can do..

sovende

So, I’m curious. What is/was the final outcome? I’m not so sure (based on the photos) if there was enough of the threading visible on the inside of the crankarm to determine left or right threads but I definitely would have scrutinized that area. My approach would have been the suggested application of penetrant oil followed by an attempt to remove the pedals in the “normal” fashion i.e. lefty-loosey on the drive side and the opposite on the non drive side.
I do realize that different cultures look at things in different ways but I’m having a hard time understanding a reality (even a French one) where pairing an item marked with an “R” to one marked with an “L” would make any sense whatsoever.
Let us know how this worked out.

vane171

Very likely, the pedals are much older than the cranks or, at the very least, are very different styles.


Yes, I checked it and it is like you say. But that doesn't seem to make a sense. I always believed that right and left hand screws when it comes to pedals is to prevent them unscrewing when the pedal bearings get stiff.

Right foot pedal, DS one, would in this case of right handed thread get undone in forward pedaling action since that would tend to generate anticlockwise force that unscrews the right handed thread.

AeroGut

That's an old wives' tale. Another version says that if the bearings completely lock, they'll unscrew so as not to break your ankle, but even a really really really bad set of bearings wouldn't generate much torque on the spindle.
The correct reason is to keep the spindle from unscrewing due to precession, which is the very small movement of the spindle in the crank . There's a pretty good explanation on Wikipedia: https://en.wikipedia.org/wiki/Precession_(mechanical)

In order to avoid unscrewing, they're set up so that the precession results in tightening on both sides, which is why pedals can be such a bear to remove even if you don't crank them in tightly when you install them.

Pop N Wood

I'm sure he figured it out by now but there is enough of thread visible that one can tell which way to turn to loosen the pedals.

My dyslexia somehow prevents me from having pedal turn direction burned into my memory. But looking at the thread pitch works everything for me

jo_lacs

I did inspect the small amount of crank thread visible opposite from the pedals on both ds and nds. They both look conventional (ds=right hand thread and nds=left hand thread), plus I have 2 other cranks labeled "S" that came off of 2 other peugeots also with conventional pedal hole threads. I cannot see any of the pedal spindle that may show thread direction. I do believe that both pedals had been improperly installed. I think that taking these old pedals off would strip the crank threads if they haven't already. For now, I'm leaving the pedals as-is in order to keep the crank useful.
I used to think that the "S" on the cranks meant spidel but after looking at some old catalogs online, the "S" apparently stands for solida.

Geepig

Seeing the threads on the pedals is less useful than seeing the threads in the cranks. Whatever the marking on the cranks, the marking L or R on the pedals is quite standard, so if the cranks have the correct thread direction you should be OK.
See if either pedal will loosen a bit.

jccaclimber

There are enough threads on the inside of the crank to determine rotation direction.
Not the case here if that's a permanently fixed double, but every now and then I've come across a RH thread non-drive crank paired with a LH thread drive crank that's either without rings or a single. That's the typical configuration for a tandem captain's crank, timing ring on the left and no ring on the right.