keidal

Hello,
Can anyone please give me advice on which Campagnolo rear derailleur might be suitable for an 8 speed Sachs cassette, which is screw-mounted on to a Campagnolo Record rear hub ? The rim is a Mavic G40 and probably dates from the early 1980's.
The derailleur fitted to the frame when I obtained it was by Shimano, although I believe that the frame probably dates from the late 1970's, with friction shifters.
Or would it be more sensible to forget the 8 speeds and go for say, a 6 speed cassette. In this case, would a Campagnolo Nuovo Record or Super Record be appropriate ?
All the other components are Campagnolo.
Thanks.

Bianchigirll 

It sounds like you have a freewheel not a cassette. you could use most any Campi RD depending on what shifter you intend to use


Will this be a friction shifting bike? or do you intend to use an index system?


Sachs freewheels are spaced for shimano index systems

Grim

Kind of confused as to what your looking for. Really a lot of important information missing from your question. Need to fill in a lot of blanks like what crank you want to run and the tooth counts on the rings, how you want to shift (friction or index). Even some information on what frame you are running might factor in.


The difference between the same year Nuovo Record and Super Record is one has titanium in it to make it lighter and about double the price. Its otherwise pretty well identical in operation.

Assuming you are using friction shifting, the most important parts is if the derailleur can handle the largest ring. www.velobase.com has a pretty complete listing of derailleurs and most will list the largest ring it can handle.

The Next important part is if the Derailleur has enough swing and that might come down to somebody having tried it before. The Nuovo record was only used on bikes that came with 6 speed. However 8 speed the spacing changed and the width of a 8 speed is about the same as a 7 speed and usually you can get away with that.

Fill in some blanks and you can get a better answer.

Chombi

Hmmm... I always thought the 7 speeds were the limit for 126mm DO spacing and you need to have at least 130mm if you want 8 speeds......unless you're willing to spread the rear triangle wider by cold setting and realigning the DOs....or just squeeze in the wider 8 speed hub and let the skewer pull everything together to line up.....

Chombi

keidal

The frame is a Fiorelli built Coppi, the cranks are 52/42 Campagnolo GS. I have checked it is an 8 speed freewheel, the largest sprocket has 22 teeth.
The frame came with a Shimano 105 rear derailleur but I would prefer a Campagnolo unit even if it means me buying a freewheel with fewer speeds. The friction shifters are on the down-tube.
If you refer back to an earlier post, you'll see that the frame had decals PLEINT when I bought the complete bicycle but which readers soon identified as a Coppi. Who Pleint was nobody seems to know but the Mavic G40 rims had rotten skinny 20mm tyres on them, so somebody was keen !
I am rebuilding this bicycle as a Coppi, it is now resprayed white with red Coppi decals.

Grim

I was thinking it was 8 but I guess you are right. I was thinking the 1055SC (8s)I have was a 126 but I think your right that its a 130mm.

I do know that after 6 speed the spacing got less and less depending on the manufacture. Suntour 6 was 5.mm and "regular was 5.3.
According to Sheldon https://sheldonbrown.com/gloss_sp-ss.html#sprocket

Interestingly there is 2 different spacings for the Sachs 8 speeds on his chart. Till 97 it was 5.0 and 98 up was was 4.8. If its a 4.8 is over all width wouldn't be much more then a shimano 7speed.

That said its a freewheel so the width will be determined by the hub. It might fit as is. If there is a spacer or even a washer on the non drive side you could swap it to drive side and redish.

Grim

Damn! hope its flat around you 22/42 sure aint for the faint of heart on the hills. That being your lowest combo and friction you can get away with pretty well anything you could want. The problem will all be if it has enough swing to make it to the smallest gear and largest gear. I suspect the smallest will be more trouble.. Again you might need to swap a spacer from one side to the other and redish the wheel to get a little bit of clearance on the drop. You are playing with fraction of inches. You might even need to add a thin washer on the derailleur hanger as long as you have good engagement of the stop.

8speed freewheels are not a common item so kind of uncharted territory. Its going to be a try it and see. Always easy enough to go back to a 6 or 7.

Bianchigirll 

I have my C-Rec HF hubs respaced for an 8spd Sachs FW. I am not certain just what the spacing is on them though. they work OK, but I need to be a bit carefull about riding over anything thicker than a dime.

Keidal; If your bike is working fine as it, then any Campi RD should work OK however a newer one (Chorus era and newer) will shift a bit better because of the slant parrallelogram design.

Pics?

Chombi

Athena RDs go for pretty cheap out there (I've seen NOS examples go for like $50) considering that it's identical to the early version of the Chorus, which is more expensive and not as easy to find.

Chombi

Bianchigirll 

Actually they are completely different.

Original Chorus



The original Chorus was designed to allow you to adjust the angle of the parrellelgram/body for wide or narrow ratio freewheels

Original Athena

old's'cool

Hell, I'm rockin' a 51" low gear (not counting the granny, which I don't use) on my somewhat hilly commute (certainly ain't flat), it's not so bad. Looking forward to getting into better shape, as the weather improves.

Chombi

Uhmmm....., I was referring to these:

Chorus:



Athena:



Not really familiar with mid/late 80's Campagnolo models, but maybe the ones I'm referring to are either newer or older generation Chorus and Athena RDs.

Chombi

Captain Blight

I'd really like one of those Gen I Chorus mechs. I really like the adjustable-cage-angle idea.

vettracer

Chombi;13818918]Uhmmm....., I was referring to these:

Chorus:



Athena:



Not really familiar with mid/late 80's Campagnolo models, but maybe the ones I'm referring to are either newer or older generation Chorus and Athena RDs.

Chombi[/QUOTE]

The top Chorus and Athena shown are are first generation and the second set which look identical are later versions. I have the first generation Chorus and am currently using it on a 10 speed cassette 11-23 and it works perfectly. It probably has enough b screw adjustment to run up to a 25 cog.

Ecrevisse

Any Campy 8 speed rear derailleur will work.

keidal

Thanks for all your views. When I bought the bicycle, it looked as if it had been in a barn or similar for a couple of decades; the chain was rusted solid so I couldn't see if the Shimano 105 rear derailleur worked satifactorily with the 8 speed Sach arrangement. The shifters were also "solid" and wouldn't move. It probably did operate OK, there were spacers on the drive side and the rear spacing is 130mm. There were no spacers on the LH side.
It sounds like I'll have to try a Nuovo Record derailleur with the 8 speed set-up as it was and hope for the best. I understand there were several NR models, so let's hope I pick one that works - that is, unless you've any other suggestions.
Thanks again for your interest and help to this old codger [nearer 80 years than 70] and who is determined to ride this bicycle, as soon as possible !