Peugeot PX-10(?) crank question
 

Hi all - my commuter bike is a Peugeot PX something, maybe a 10, that's older than I am, and I love the thing to death. No need for a new bike if I can keep this baby alive!

The latest problem was the crank seizing up, which I mostly fixed by removing the left side crank and cleaning and re installing, and re-lubing, the ball bearings. That made it mostly functional, but it was still a little stiff and since I was in the zone I tried taking the sprockt side crank off as well, which I did.

The problem is how to remove the shaft cover thing on the sprocket side. It's an octagon, and looks to be 1.5" diameter. I tried with my big crescent wrench, but I can't get a good enough grip on it without it slipping off, and I'm afraid of rounding the edges, so I don't want to push it.

Question is, is there a tool for removing/tightening/loosening this thing? (and what's it even called? sprocket side ball bearing cover? lol)

pics attached

Thanks!

Geoff

Unfortunately, the forum won't let me post a picture I guess because I'm too new I suppose? (I can DM to anyone who want to see, or maybe I'll figure out a workaround after I post this.)

Dummy post to get to ten so i can post pics

And one more

https://live.staticflickr.com/65535/...0b12b6f7_z.jpg

That is the "fixed cup," which is left hand threaded. Edit: incorrect as stated in subsequent posts.

Here is Sheldon Brown's bottom bracket cribsheet (link).

That is almost certainly a French-threaded bottom bracket, and therefore the "fixed" cup has a tendency to loosen up over time if not secured very well.

It is not unusual that this cup is very well-fixed indeed, if it has not loosened up on you. It may be wise to service the rest of the bottom bracket but leave that cup in place.

Ah, ok -

Can I get to everything from the other side then? Happy to leave it on if it's better to do so!

Probably French threading, so counter clockwise to loosen.

While not ideal, you should be able to manage cleaning and lubing with that cup left in place.

Late to the party - never mind.

...yes, this is what you want to do. Some of those fixed cups in old French frames are stuck in there pretty solidly. If the bearing surfaces are still smooth inside, (look inside with a light, after you wipe out the old grease), leave it in place and run a bead of grease around the perimeter, to hold the new bearings. (In a case like yours, I usually buy and install new ball bearings. They are pretty cheap. Buy the proper size.) Then you slide in the spindle, and install the adjustable cup, which also has bearings stuck in there with a bead of fresh grease.

https://cimg4.ibsrv.net/gimg/bikefor...3e42ecb593.jpg


If you can find one, this would also be the time to install a plastic shield in there, but it's not required for the thing to work.
The spindle may be asymmetric, in which case the longest taper side is the drive side, and goes in first.

Its not better, just easier, often times way easier.

They should always be taken out for proper service of cup AND threads, many here disagree, so be it. :twitchy:

There is a simple if not a bit convoluted process that I always use to get them out, every single time, period. ;)

Welp it was pretty easy getting to the bearings and removing the shaft from the other side. Got everything out, cleaned and reinstalled with new grease in under half an hour.

Thanks for the help! It feels much much smoother than before. I did have to grind down the inside of the crank arm a bit as it was binding when I tightened everything up, but once that was done this thing spins better than it ever has.

Now I just have to figure out how to get a seized pedal unscrewed from the sprocket side crank arm. It's in there reeeeeeal good. I've put the crank arm in my bench vise and still cant get the pedal to budge. Soak in WD40 or something?
https://cimg7.ibsrv.net/gimg/bikefor...5f3d4afbdd.jpg

Soaking with penetrant might help although with galvanic corrosion it won't penetrate. You might try an acid like vinegar.
Aluminium will expand more than steel when heated so hitting the spindle with a creme brule torch for a bit can help, though some say this is sketchy.
I usually get it with just a long pipe over a wrench. The amount of force the 15mm flats can take before a wrench would cam out is a lot. If you haven't stripped/snapped a wrench it's not really stuck.

What I did the other day when a wrench actually did strip out was take the body off the pedal and stick the axle in a vice and have a couple people wail on the crank to turn it, that worked.

Hold up sorry I think it's possible the crank is threaded for french pedals and someone has just jammed a regular set in there?
Others will have better advice on that then. I think you might possibly be destroying the crank if you remove them

.
...for really stuck pedals, I heat the area around the pedal shaft where it goes into the crank arm with a MAPP gas plumber's brazing torch, but you can melt aluminum with one of those, if you get it too hot. Don't melt the aluminum, and if you have some Freeze-Off, do a couple of heating and cooling cycles. Unfortunately, when a pedal is really seized in an aluminum crank arm, sometimes some of the threads come out welded by corrosion to the pedal. But don't worry about it unless it actually happens. :)

If you had to grind on the crank arm, the spindle is in backwards or something else is wrong.

You should NEVER grind on a crank arm, it is weakened at that point now, you need to sand and smooth that area now, at the very least.

That pedal is the wrong thread for the crank and without mad skills and and a standard pedal tap, you will be hard pressed to get it out and corrected.

We can see from here it is not seated for being cross threaded, you might be able to overhaul it and keep it usable by 'leaving it in place" too. :twitchy:

...there is a relatively simple repair for this, but I think he'll have trouble finding someone to do it.

Between you and I, he now knows where at least two of us are, although even I might be hesitant to work on this with it not being my own. ;)

If you did not remove too much, smooth as suggested and then I would leave things as they are, pedal and all.......
Good Luck, Ben

Thanks for the heating/cooling advice, guys, great idea! I might just let it soak in the oven at 200 for half an hour and see if that loosens things.

FYI I did put that pedal in myself, almost 20 years ago. I don't remember exactly, but I'd guess I didn't cross-thread it or anything. The mate on the other crank arm came out just fine, although it's a newer arm and possibly was replaced by a bike shop.

Re: the grinding on the crank arm. I should have said "sanding" but the point is well-taken. I'll keep my eyes on it. The inside of the arm was rubbing against the adjustable cup somewhat. I didn't have to sand much at all to get it to turn without binding when I tightened it down. FYI it's definitely not the original crank. (Although the sprocket side is, AFAIK.)

Thanks again all.

Ok, well it sounds like none of this should be surprising and maybe the problems we usually see with these were encountered years ago, some by you and may have been at least partially if not mostly mitigated at the time.

That being said it also sounds like some of the fallout is revisiting now and you are managing to wrangle it yet again.

We really like to dig into this exact thing as you can tell but we usually need more blow by blow to keep up.

it would have been nice to have these gory details going in as we could have dispensed with our standard tack that usually applies 90% of the time.

Glad you seem to have gotten the best of it again and hope it gets you down the road. ;)

If you really want to get it out you pretty much have to bolt whatever tool you use to the cup so it doesn't slip.

​​​​​​https://www.bikeforums.net/classic-v...-cup-tool.html

The pedal came off the non drive side (left) crank arm because it is modern and compatible with your pedals. The drive side original crank arm is likely French and the pedal you forced on did not have matching threads. Also that replaced crank arm does not match the spindle axle thing and goes on too far. Stick with it. We learn as we go. A PX-10 is a nice place to start. You will have a very nice rider eventually.
link to other thread with a picture: https://www.bikeforums.net/classic-v...d-pueugot.html