Another french classic : 1938 Narcisse

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bduc61":2z8xlhnp said:
Well guessed, the grease seals are felt !

and the right side is most probably very similar to the left but without bolts - see pic below - have to undo it

By the way why did you say it could be taken out on the right side ? I would have thought the other way around ?

As to me the bolts compress the left handside spindle part so that it can not move outside to the left - the spindle being blocked against a move towards the right by the right washer blocked by the open ring - the right bearings being blocked to the right by the same washer and to the left by a shoulder on the spindle ! ouch dunno if it is understandable and making sense at the same time :mrgreen:

Your bottom bracket has a lot more in common with a lathe spindle than a conventional bottom bracket see the attached photo, instead of a lathe chuck imagine a crank arm and chain ring. Timken bearings are shown in the photo, imagine annular contact ball bearings instead. I believe whoever designed your bottom bracket spent time in a machine shop as it's constructed like a lathe spindle.
Let's assemble the bottom bracket, first the outer bearing races are pressed into the bottom bracket shell until contact is made with a step or shoulder internal to the shell.
Next the right hand inner bearing race is pressed on the right hand side of the spindle against the shoulder and then the ball bearings and retainer is placed on top of the inner race and inserted as an assembly into the outer race through the right hand side of the bottom bracket.
The left hand ball bearings and retainer is set in the outer bearing race and the inner bearing race is a slip fit over the shaft until contact is made with the bearings and races.
The two nuts controll bearing preload, the snap ring, dust shield, and felts are not a structural part of any of this and only keep the grease in and the weather out.
The bearings in your bottom bracket are similar to the type used in Maxi-car hubs and old school high speed rotating machinery, they are very stout and handle axial and thrust loads. Your bearings have numbers stamped on the edges of the races and should be available at any good bearing house.
I hope this helps, the reason I said "Wow!!!" in my first post was I recognised the construction from my machine shop days. :shock:
: Mike :D

SpindleCrossSection.jpg
 
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thanks for explanations ;)

Hence undoing looks difficult . If would wanted to undo it, the chance to damage the bearings is pretty high ? no ? I don't really see how it could be done neatly ? or it could be done be reassembling woud be the real tricky part ?
As having the whole spindle go through the left inner bearings is possible but tricky ? and it would push the inner right race out ?.
By the way the left bearings outer race bears no mark whatsoever - need to undo the right :idea:
looks like a 36 to 37 outer diameter
 
I don't think you should worry too much about damaging the bearings. They'll be replaceable and even in the most obscure size will only be €3-€4 each.

My first port of call would be to get the drive side of the bottom bracket onto something sturdy with the axle poking through the middle (I'm thinking a large vice) and give it a couple of good blows. I think it's most likely that the bearings are pressed in and held in place by the threading on the axle. Like Mike says, it's probable that both the axle and bottom bracket shell are stepped, so you need to drift that drive-side bearing out by tapping the axle on the non-drive side. Then use a suitable drift (e.g. socket and extension bar) to tap the non-drive side bearing out. DON'T hit the axle itself! Put an old bolt in the axle and hit that instead!

Edit: I'm liking this bike more and more though - quality bottom bracket setup. I'm loving the engineering.
 
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The bearing number for the outer race you can't see because the wide side of the bearing has the marking and its setting against the step in the bottom bracket. Spray the works down with penetrating oil on the left hand side and let it sit for a while, it should not take a a lot of force to disassemble, it looks pretty good on the inside all I saw was dried grease and no corrosion in your photos. Jonny69's advice is excellent I would add a bucket with a few rags in the bottom to catch the pieces as they fall out the right hand side (remove the dust shields and felts). I am betting that the ball bearings and retainer are separate from the races, and once the spindle clears the left hand inner race everything else will fall out of the right hand side of the bottom bracket. I am sure that this was designed to disassemble for maintenance, so give it a good whack and see if anything moves.

Best Wishes: Mike
 
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small diversion :idea:

I said that I purchased some DT competition 2/1.8 spokes for my rear wheel.
Alas , when they arrived I realized the flanges could only accomodate 1.8 spokes - the hole was not big enough :roll: - remember initial spokes were 1.8/1.5

I also said these Robergel spokes were as rare as a hen's teeth , I have been looking for some for ages in France

well by sheer derision , I made a call to "Saint Expedit" patron of the lost causes in France :idea:

A week after, by sheer luck , I found an old box on the major small ads site in France that should do the job- they are 1.8/1.6 - they were advertised as 290 mm but by reflex I checked and found them to be 305 which is about the right length - its about the first box I seee in the last three years :cool:

So the poor "lost sheep" I am is now contrite and I'll light a candle next time I go to church :oops:

And if you have some Robergel spokes, will be happy to give them a new home :idea: ;)



 
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In front of the rugby game yesterday :idea: ( ouch - that was tough for the frogs in front of the spaghettis !)



 
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