Wanted: Vintage rear derailleur (circa 1979)

Hi all.

I am in the middle of refurbishing a touring bike from the late 70s (1979) but my rear derailleur main spring is very weak. The chain does not wrap properly arround the free wheel and jump if you put pressure on the cranks.

If it could be shimano 600 to match the front derailleur that would be great, but I am not too fussy about that, I would just love to fond something consistant with the style of the bike, cheap (£10 max), and that have still strong springs to hold the mechanic...

Here is how it looks like:

Also, sorry to be a pain but I would prefer to buy it from someone in London so we can meet in person at some forum drinks, I can't be asked to go thru something with postage involved...

Thanks!

Loic

can we have a pic of the whole bike so that we can get an idea of what might suit it please.

can we have a pic of the whole bike so that we can get an idea of what might suit it please.

Dear CoppiThat,

Well, I would have like to go thru every details on the bike and sort everything out, and then only post it on "current project" but it is so kindly asked, so here it is...

Hope that helps!

Loic

i might have something, you can have it for free.
phone me as i'm not going to be near a computer in a minute.

i might have something, you can have it for free

Thanks! Do you have more details?
I realise that I did not specify I would like it to be from a similar "range" as shimano 600, more or less... I am actually a bit fussy there finaly... sorry.

BTW, just a though... Does anyone know if it is possible to "re-tight" the main spring on these old derailleur, or to replave it with the spring of of a newer derailleur... I doubt it as it seems to be sealed, but I'd rather ask to be sure...

Loic

can we have a pic of the whole bike so that we can get an idea of what might suit it please.

Argh!! don't be upset my friend, I was just kidding... Here are my best pics so far of the bike (not kiding this time...):

And details of the lug work:

Voila!

Szia

Loic

hmm well they didn't have carbon seat pins in those days, or curved cranks either but am I being a purist/pedant/etc

I have a shimano 500 off an old 70's frame I'm working on which i was going to post up shortly. It's yours for a tenner if you want it.

i've got a simplex one that would suit, if the other offers fall through

hmm well they didn't have carbon seat pins in those days, or curved cranks either but am I being a purist/pedant/etc

Ouch! that hurts!! Mainly because you are quite right, I know...

I don't disagree with you... But please note that the carbon seat post is temporary only and should be sorted by the end of the week. The original one was a little too short for me. It will be a plain and simple tubular aluminium post, without integrated clamp, as the saddle that is to go on it has weird flat rectangular railings and has its own clamp. I am sure that you will disapprove that this saddle is French (Pearl) and is from the 50/60s (just a guess)...

Re the cranks, I agree too, but the original ones were really cheap (very basic SRs) so I've put those for the moment as they were available from my shed. They are not ideal, but I don't feel they look outrageously modern on the O/A picture... I would not mind something better but now I want to ride the bike and not to spend too much money on it... If you have something to offer, please don't hesitate to tell me!

Szia

Loic

I have a shimano 500 off an old 70's frame I'm working on which i was going to post up shortly. It's yours for a tenner if you want it.

Thanks but I would like to avoid postage just for a derailleur, and meet someone at any of the London's drinks instead.

L

i've got a simplex one that would suit, if the other offers fall through

If Stallion Leg's one does not fit, I'll probably ask you a picture... Saying that I though Simplex stuff from the 70s were not that good anymore... But I would happily admit that I am wrong on this one...

Loic

in Bethnal green - pic up in 5 mins.

ah yes, I remember my nice cheap Simplex rear mech bust just after the turn in a 25 mile TT, it just went twang! and I was stranded.

It was then off to a Huret rear mech, then Campag Nuevo Record when common sense clicked in...

in Bethnal green - pic up in 5 mins.

Sorry I though you wrote something about postage... I'll first try to check Stallion Leg's one and come back to you if no luck! Thanks

Loic

No problem. It has a bit more surface rust than i released so you can just have it if you want. Should clean up ok and runs well.

(Sorry - massive image!)

Hi all

Looking a bit more in the mess of my shed I found a derailleur from the same era, only an Altus LT, but it looked almost identical to the 600.
Comparing the two, it seemed that the Altus had more "punch" in its springs that the 600, but once fitted, no luck, still the chain would not grip on the block...
So I sat down yesterday evening to try to understand what the hell was wrong.
I think the problem is a mix of problem... I originally had to put a new chain as the old one was really elongated and had some washers broken between the plate links altough structuraly it was still OK. The old chain was cracking a lot on the free wheel but had a good grip on it, even with the shimano 600 derailleur. The new chain, with the same lenght and same derailleur was not holding on the teeth and was jumping when applying pressure on pedals... So I tried to shorten the chain but this did not work either as the chain was still not wrapping enough arround the block (which strangly was not a problem with the old chain...)
I finally became really impatient with the whole thing and tried with the brand new shimano derailleur that is fitted on my other bike to check if the problem was really coming from the derailleur and not the fact the chain is too new for the block (visually it does not look too bad)... Anyway it worked perfectly, good grip, all smooth... I am relieved.

The main difference I noticed between the old and the new modern derailleur is that the old ones seem not to have a main spring that give resistance to BOTH movements towards the back AND the front. I will try to find another new derailleur to put back on my other bike, and that will be the end of my troubles...
(something more or less like that)

I know it might be too modern for the bike, but as I said, I just want to ride it for the moment, I can't be asked looking at it anymore, (and I don't feel it looks so bad...)

Phew! that was a fastidious post!

Thanks guys to all your offers and to people who took time to take pictures!

Szia

Loic

Postscript, I have an immaculate Shimano LX from a Dave Russell circa1982, that I will never use. Backup?

If Luic doesn't want it, I'd like to take that off your hands, fiddy.

That's fine, Loic seems like he's sorted, but will wait til tomorrow!

That's fine, Loic seems like he's sorted, but will wait til tomorrow!

Pm sent... I am still looking for something to put back on that bike I took the SRX from, so maybe...

Thanks

Loic

For your information, that derailler allows you to service the spring pivot and set the tension. It is possible that someone has incorrectly re-assembled it in the past and the spring just needs to be wound round one turn to give tension. It is also possible that it needs cleaning and re-greasing inside that pivot.
I have one of the same and i've serviced it in the past.
I can't remember if the spring has more than one locating hole (some mechs have more than one housing hole to enable varying tensions to be set) but you should not be afraid to get in there!
6mm allen wrench, regular clockwise thread into cage.
Top tip would be to (first) remove the stopper that stops the cage unwinding the spring. (holding the cage away from the stopper so as to not 'hurt' the threads). Moniter how far it then unwinds. Now with no spring tension to go bang, undo the allen bolt from the cage.
Disassemble, clean, pause to appreciate beautiful engineering and attention to detail, re-grease and enjoy years of smooth operation!!
Gregx