skou

Hello bikeforum!

I have bought a Peugeot PBN10, and I already love it! It is a pleasure riding a ~12 kg bike instead of a ~20 kg bike.

Thing is, when I got home and gave it a makeover, I noticed that at the point where the front wheel points directly forwards, it feels a little bit like if it "locks in".... It is kinda tough to describe, but it is like that it "wants" to point directly forward and won't fall out to one of the sides if I either lift up the bike or walk it by holding the saddle.

I can of course turn it as I want to, and it is barely noticeable when I'm riding the bike, it is most present when it holds still.

Is it meant to be like that? This is my first vintage racing bike.

I am working on a video to upload for you guys to see me "demonstrating", lol.

Cheers!

dedhed

WizardOfBoz

What can happen with bearings is that if they receive a shock, it can force the balls to dent the bearing race. This is called "Brinelling" (there is a Brinell method for hardness testing based upon making dents in metal). Too, if a bike sits in one position for a long time you can get corrosion that forms detents in the bearing races. Last, you can bend axles (or less frequently headsets) so that the cones and cups aren't aligned, which can cause the searching phenomenon you observed.

Take the stem out of the headset. (Helpful hint: do this with the headset over an old towel with the bike lying down if you suspect that you have cups and cones with unretained bearings. Or if you don't know that you don't. This will limit bearings flying all over the place. Remove the fork and clean the cups, balls and cones (mineral spirits in a big plastic peanut jar, and an old toothbrush is what I use.

Inspect the bearing cupes and cones (the lower cup and upper cone will still be in the bike frame). You should be able to see if there's dents or rough spots. Worst case, you need a new headset. Or, you need to go on ebay and find a matching cup and cone. If the bearings look good check the fork steer tube with a straightedge to check for bends. Let us know what you find.

BTW, if the effect is very small and you don't notice it while riding, you could just clean the thing up and regrease the thing and reassemble. Easy to obsess about things that don't really matter.

jideta

me thinks he's talking about the rake of the fork and how the steering isn't quite 'neutral'

Andrew R Stewart 

The OP talks of lifting the front wheel off the ground and leaning the bike a bit, no wheel revolution or bike being ridden so no fork geometry issue. The description is classic dented headset bearing races and Wizard got it. Andy

skou

Thanks! A little damned if I bought a flawed bike. I will definitely try take it apart asap, and take some photos for you guys to help me!

Hopefully it will be enough to regrease it and reassemble it, as I don't know where to get spare parts from haha.. I guess the market here in Denmark isn't quite big in terms of old vintage peugeot bicycle spare parts, what do I know....

Wilfred Laurier

This certainly sounds like a pitted or brinnelled headset bearing race. The cheap solution is, provided it is a cup-and-cone serviceable headset, replace the bearing balls, but reassemble without the original cage holding the bearings in place and use one extra ball than would fit with the cage. This will put the new balls out of phase with the pits in the bearing races.

NB. this method is much more finicky as keeping the balls in place during assembly is a bit of a pain, but if you put a fair amound of nice thick grease on the bearing surfaces it will keep the balls in place as you work. It may be necessary to position the bike such that the steerer tube is completely vertical during assembly - this will help prevent the balls from moving around or trying to roll off into the head tube.

WizardOfBoz

It's not flawed, it's an opportunity to learn! A bonus: it sounds like it's eminently ride-able in the meantime.
You may have more access to old Peugeot parts in Europe than we do here, though a lot of Peugeot bikes were sold here.

dedhed

Given that it's a Peugeot, depending on vintage, be aware it may be French threaded and a harder to find item. You also need to do some research into "STACK HEIGHT" should you require or want a new headset.
It's not always simple plug & play, especially with French bikes.

https://www.sheldonbrown.com/velos.html

https://velo-orange.com/products/vo-...thread-headset

skou

Well well well. I took the headset apart, and to my surprise was it greased up quite good. Anyway, I cleaned everything up and regreased and adjusted the whole thing, and now it runs smoother than ever.

If I tightened the adjustable race till there was zero play, the fork turned quite smoothly, UNTIL I tightened the locknut, then the issue introduced itself again. So apparently the locknut applies extra pressure to the adjustable race which would result in the same issue I had to begin with. Then I readjusted the adjustable race just enough so there was a small amount of play, and then tightened the locknut which then eliminated the play and allowed the fork to turn nice and smooth.

I took some photos of the races, and I found them to be in "OK" shape, age considered. I don't know how useful they are, but here they come:

Adjustable race


Upper head tube race


Lower head tube race


Crown race #1


Crown race #2


I hope I use the right terms, correct me if not. I know the lower headtube race seems quite dented, but I drew a screwdriver carefully across the surface and couldn't feel anything at all, so I guess it's just visual.

WizardOfBoz

Adjusting cups and cones, while not rocket surgery, does take a little bit of touch and experience. When you get the top cup adjusted perfectly, you back it off a bit to allow for the tightening of the locknut and the movement of the cup because of the locknut. But I think you've done this before...

So....

Ding ding ding ding ding! I think we have a winner! Photo three shows what is called the lower cup (you call it the lower headtube race, which is perfectly fine, too). The pic shows little scuff marks. You noticed this. Your screwdriver won't feel them, but your bearings (especially if tight) will.

My advice would be to back off a little bit on the bearing preset. What I do is get it just about right, then alternate tightening the locknut onto the top bearing cup (tightening the bearing preset), and backing off that bearing cup (loosening the preset). You may still feel a little bit of that preset/bearing wear after you're done. Since your bearings will be clean and well-greased, and you say you don't notice this while riding, you can either choose to ignore it and enjoy riding the bike, or you can find a replacement and fix it. Me, I'd just ride it but its your bike and your call. From your posts, it's certainly rideable and safe.

BTW, replacing this involves using something (there are specific tools, but you can use a piece of 16mm or 1/2 pipe) to tap the lower cup out. Then you use a press (or a piece of all-thread with some washers and nuts) to press the new race into the frame. Important to get it in straight and completely seated. Not terribly difficult, and kind of nice to achieve.

Good luck!

Mad Honk 

Wiz, you got this one! ( Nice catch) The dents in the lower race are enough to create the locking in place. Lotsa miles will do this to a headset. That lower race should fix his problem. Smiles MH

skou

Actually, this was my first time doing this. But it was exactly what I did. Actually I think those scuff marks comes from all that time where the bike hasn't been used and has been standing still instead. Couldn't that be possible? You can almost see how the bearings were aligned inside the cup.

I will definitely just ride it and see how it works out at first! To me it is perfectly fine, and I guess one can't buy a ~40 year old bike and expect it to ride like a new one, although I feel like it does now.

Thank you so much for helping me out on this.

Do you by coincedence know how to adjust the front and rear derailleur on Peugeot's friction shifters?

WizardOfBoz

So first, if the bike was sitting around it's perfectly plausible that there was a little corrosion at the contact points. If you don't notice it while you ride, enjoy!

So, you could post a pic of the derailleurs. Or confirm that your setup looks like the following pics. Once we confirm the type of equipment, it will be easier to give direction. Are the shifters not working well?

2manybikes

You got it right!

JohnDThompson 

If the pitting isn't too bad, sometimes you can eliminate "indexed steering" simply by using loose balls instead of retained balls. Often you can use at least one more ball than the retainer held, which means the balls will no longer automatically settle into the pits. Another thing that may work is removing the crown race and re-installing it in a slightly different orientation so the pits no longer line up with the balls.

Ultimately, "indexed steering" means the lower stack is worn and ought to be replaced. If you can find a headset with a lower stack height close to that of the current headset you can just replace those parts. This is particularly helpful with French bikes like your Peugeot, which may have a metric thread steer tube. The upper threaded parts seldom wear out, and this means you don't need to search for an entire new metric thread headset.

skou

Unfortunately I'm not able to take photos of the bike right now. I have posted some photos of it in this thread, hopefully you can use those, else I might have to post some when I can:
https://www.bikeforums.net/classic-v...y-peugeot.html

If I remember correctly, it says Peugeot on the rear derailleur! The shifters are working well I'd say (roughly). I just noticed that the chain won't shift down to the smallest gear in the rear, which is why I thought that the adjustment could be a hair off.

WizardOfBoz

Ok, if the derailleur says Peugeot, it's probably a rebranded Simplex. Some models looked like what I show above (with plastic end pieces holding the parallel arms) and some looked like below with metal end pieces. Neither were very outstanding in performance. I haven't adjusted one of these since 1973, so I'll let others give you guidance. But its not rocket surgery.

skou

Fair enough!