I was given a rather spangly Campag Nuovo Record rear derailleur a while ago, but when I tried to fit it this afternoon, I found out that it wouldn't play nicely with the 24 tooth block. I got either a oodles of chatter as the top jockey wheel was too close to the block, or a jammed drivetrain when using big / middle combinations if the chain was shortened any further.
The bike's a gas pipe Raleigh, so the Nuovo Record is really a bit too good. The gearing is 2x6, with friction shifters.
Any ideas what will work, and look halfway OK? I've currently got an old campag front mech and cranks, so a Campag mech that will work would be a bonus. If not, will the old swirly pattern Shimano 600?
I think the old Campag gears have some sort of number stamped on them that refers to the maximun sprocket size....could be wrong.
Also a 24 tooth freewheel was at that time considered enormous 19 and 21 were usually the max. We were proper hard then you see.
Not sure what's happening.
you have adjusted the screw into the hanger.
Is it deffo six speed, not five.
And it won't play with a compact, 36 minimum.
Oh and they did got o 28t.
It will bloody well run with almost anything. I currently have one running on a 28/38/48 triple with a similar aged front mech. Modern 10 speed Campag shifters, 10 speed Shimano cassette and a 28 big cog. I am careful not to run 7, 8, 9, or 10th on the little ring or 1, 2, 3, 4 on the big ring. 1 and 10 are avoided in the middle but thats common sense with any mech. shifts are 9/10 on the big ring and fine anywhere else.
What's happening is that the top jockey wheel's getting too close to the block. On the NR, the pivot at the mount is completely free to move (assuming mine's not been messed with), whereas a modern Shimano mech is sprung, with a B-pivot screw). When you talk about adjusting the hanger screw, there isn't one in the B-pivot sense you get with a modern mech - unless you mean actually doing something with the mounting bolt?
Shortening the chain (too much) adds enough tension for 39/24 to work happily, but jams things as you get half way up the block in the big ring. A length that allows you to run 52/24 without destroying things leads to lots of chatter as the top jockey wheel is too close. As I understand it, spacing out the freewheel can help, as the jockey wheel moves up as it moves closer to the centreline of the bike, but I've very little idea of how all these old freewheels work.
In theory the NR should be happy with a 26, and plenty seem to have them running on 28s, but not on my bike. I suspect a contributing factor is that my frame needs an adaptor claw, which moves the wheel forward in the drop out, and therefore down a little closer to the rear mech.
I've got a 39/52 up front. The mech's a 1973 model.
'73' would have been five speed, but as mattsccm says it's working across a huge range.
I would have run that gear back then, but as for the workings of them I can't really remember.
I'm clutching at staws here, but. Could it have the wrong jockey wheels? I seem to recall the old ones being virtually smooth, could be talking out of my **** though.
Jockey wheels are right as far as I can see from comparing with web photos - possibly not Campag originals, but certainly the right size & shape.
"old swirly" shimano may well work! depends which one you mean...not that I'll know the answer...