Campagnolo: Trash or Treasure?

[Dave Mayer]

Someone just gave me a bizzarre late-80's Campagnolo rear derailleur. With a little research, I've
figured out that it is a Chorus A-B unit. It is light and looks very well made. I stripped it apart
and put it back together; I found that it has the unique feature that you can adjust the slant of
the rear parallelogram. Set in the A position, the slant of the cage matches a close ratio
freewheel, and in the B position, the slant of the cage tracks a bigger ratio freewheel. It has no
spring in the upper pivot...

I've checked the geometry of the derailleur. The cage is identical to modern Campy units. Set in the
B position, the parallelogram slant is the same as modern Campy road units. The only difference is
the where the cable terminator sits relative to the derailleur cage. I can compensate for this
difference by mounting the cable on the top (opposite) side of the mounting bolt.

Once this is done, the overall geometry of the derailleur should be the same as a modern Campy unit,
and it should index with Ergopower shifters. Right?

Here is my question - which I cannot find a satisfactory answer on the web: Will this actually work?
I have a modern Athena unit sitting in a box. Should I waste my time fiddling with the Chorus unit?
Thanks in advance...

 

[Sheldon Brown]

Dave Mayer wrote:
> Someone just gave me a bizzarre late-80's Campagnolo rear derailleur. With a little research, I've
> figured out that it is a Chorus A-B unit. It is light and looks very well made. I stripped it
> apart and put it back together; I found that it has the unique feature that you can adjust the
> slant of the rear parallelogram. Set in the A position, the slant of the cage matches a close
> ratio freewheel, and in the B position, the slant of the cage tracks a bigger ratio freewheel. It
> has no spring in the upper pivot...
>
> I've checked the geometry of the derailleur. The cage is identical to modern Campy units. Set
> in the B position, the parallelogram slant is the same as modern Campy road units. The only
> difference is the where the cable terminator sits relative to the derailleur cage. I can
> compensate for this difference by mounting the cable on the top (opposite) side of the
> mounting bolt.
>
> Once this is done, the overall geometry of the derailleur should be the same as a modern Campy
> unit, and it should index with Ergopower shifters. Right?

Alas, no.

> Here is my question - which I cannot find a satisfactory answer on the web: Will this actually
> work? I have a modern Athena unit sitting in a box. Should I waste my time fiddling with the
> Chorus unit?

That unit will definitely not work with Ergo. It was intended to work with Campagnolo's original
"Synchro" indexing system.

The key issue is how far the cable moves for each shift. For indexing, it's better to have the cable
travel a long-ish distance per shift, because this reduces the effects of cable stretch and friction
on the indexing.

Back in the '80s, when Campagnolo had to respond to the challenge of Shimano's S.I.S., the company
was still committed very strongly to supporting their older products with their newer designs. The
"Synchro" system was intended to be compatible with existing Campagnolo rear derailers, even going
back to the '70s Nuovo Record.

Despite Campagnolo's good intentions, the short cable throw, high cable tension associated with this
made reliable indexing impossible. They tried it for a year or two, then finally bowed to the
inevitable and completely redesigned their indexing system when Ergo was introduced. Current
Campagnolo stuff uses much longer cable travel, and works great as a result.

Your old Synchro Chorus derailer is certainly a lovely piece of jewelry, but as a functioning
derailer, it's way inferior to a $20 Shimano tourney or any other modern derailer.

If I may digress, back in this era, Campagnolo also had the bright idea of making brake levers that
could be set up either with traditional exposed cables or with "aero" (under the handlebar tape)
table routing. Seemed like a good idea at the time, but the resulting overcompication obviated any
advantage this might have had.

To further digress, Shimano's indexing went through a similar progression...the original Dura-Ace
S.I.S. from 1984 used a shorter cable travel (though not as short as Synchro) and Shimano too wound
up increasing the cable travel for subsequent models.

Sheldon "History" Brown +---------------------------------------------------------+
| There are several good protections against temptation, | but the surest is cowardice. --Mark
| Twain |
+---------------------------------------------------------+ Harris Cyclery, West Newton,
Massachusetts Phone 617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts
shipped Worldwide http://captainbike.com http://sheldonbrown.com

 

[Jon Isaacs]

>To further digress, Shimano's indexing went through a similar progression...the original Dura-Ace
>S.I.S. from 1984 used a shorter cable travel (though not as short as Synchro) and Shimano too wound
>up increasing the cable travel for subsequent models.

As an addendum to Sheldon's digression, I point out that the Dura-Ace 6, 7 and 8 speed cable travel
was only about 12.5% shorter than current Shimano standards and in my experience works quite nicely,
unlike the Synchro system which is mostly a work of art from an aethetic viewpoint but not much good
at indexing the shifts.

But it is nice to look at.

Jon Isaacs

 

[A Muzi]

"Dave Mayer" <[email protected]> wrote in message
news:[email protected]...
> Someone just gave me a bizzarre late-80's Campagnolo rear derailleur.
With
> a little research, I've figured out that it is a Chorus A-B unit. It is light and looks very well
> made. I stripped it apart and put it back together; I found that it has the unique feature that
> you can adjust the slant of the rear parallelogram. Set in the A position, the slant of the cage
> matches a close ratio freewheel, and in the B position, the slant of the cage tracks a bigger
> ratio freewheel. It has no spring in the upper pivot...
>
> I've checked the geometry of the derailleur. The cage is identical to modern Campy units. Set in
> the B position, the parallelogram slant is the same as modern Campy road units. The only
> difference is the where the
cable
> terminator sits relative to the derailleur cage. I can compensate for
this
> difference by mounting the cable on the top (opposite) side of the
mounting
> bolt.
>
> Once this is done, the overall geometry of the derailleur should be the
same
> as a modern Campy unit, and it should index with Ergopower shifters.
Right?
>
> Here is my question - which I cannot find a satisfactory answer on the
web:
> Will this actually work? I have a modern Athena unit sitting in a box. Should I waste my time
> fiddling with the Chorus unit? Thanks in
advance...

I have not installed an AB Chorus in an Ergo system but it should be compatible. Since the cost is
just a few minutes' work, why not give it a go? A floating upper pulley is indicated if you have one
handy. That won't take you from "no shift" to "shift" but it could likely be the difference between
shifting and shifting well.

I for one look forward to reading your report back.

--
Andrew Muzi http://www.yellowjersey.org Open every day since 1 April 1971

 

[Twobooglie]

>Your old Synchro Chorus derailer is certainly a lovely piece of jewelry, but as a functioning
>derailer, it's way inferior to a $20 Shimano tourney or any other modern derailer.

I'd agree about not using this with modern Ergo levers - but how will it work as a friction shifter?
I'm using an original Athena derailluer with old Campy retrofriction levers on the downtube, and
this combination shifts very nicely.

 

[Dave Mayer]

Sheldon: thanks for the words of wisdom. However, I am someone, much to the dismay of my local shop
mechanics, who managed to get a Simplex rear derailleur to index with Ergo shifters. I naturally
had to try.

Sheldon was right. It didn't work, but I don't know why. I tried the cable attachment above the
mounting bolt - the result was a geometrical duplicate of all of the dimensions of a modern Campy
rear derailleur. It overshifted. I tried the cable attachement it in the normal position. It
overshifted worse. My best guess is that this unit has about the same mechanical advantage of a
Shimano derailleur. Maybe it will work with Ergoshifters with a Sachs insert.....

Seriously, this unit now sits in my historical archives, along with a Campy Synchro 1/C-Record rear
derailleur combo that shifted only slightly better.

And Sheldon is right about the C-Record brake levers with the two cable routing paths. Terrible
levers. I bought a 1986 Pinarello Montello at a garage sale a couple of years ago. Beautiful bike.
However, these brake levers, the Super Record brake calipers and the C-Record derailleur/Synchro
shifters were all pulled off in quick succession. Some cheap new stuff is better than the best of
the old stuff... Progress.

"Sheldon Brown" <[email protected]> wrote in message
news:[email protected]...
> Dave Mayer wrote:
> > Someone just gave me a bizzarre late-80's Campagnolo rear derailleur. The overall geometry of
> > the derailleur should be the same as a modern Campy unit, and it should index with Ergopower
> > shifters.
Right?
>
> Alas, no.
>
> That unit will definitely not work with Ergo. It was intended to work with Campagnolo's original
> "Synchro" indexing system.
>
> Your old Synchro Chorus derailer is certainly a lovely piece of jewelry, but as a functioning
> derailer, it's way inferior to a $20 Shimano tourney or any other modern derailer.
>
> If I may digress, back in this era, Campagnolo also had the bright idea of making brake levers
> that could be set up either with traditional exposed cables or with "aero" (under the handlebar
> tape) table routing. Seemed like a good idea at the time, but the resulting overcompication
> obviated any advantage this might have had.
>
> To further digress, Shimano's indexing went through a similar progression...the original Dura-Ace
> S.I.S. from 1984 used a shorter cable travel (though not as short as Synchro) and Shimano too
> wound up increasing the cable travel for subsequent models.
>
> Sheldon "History" Brown +---------------------------------------------------------+
> | There are several good protections against temptation, | but the surest is cowardice. --Mark
> | Twain |
> +---------------------------------------------------------+ Harris Cyclery, West Newton,
> Massachusetts Phone 617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts
> shipped Worldwide http://captainbike.com http://sheldonbrown.com

 

[Qui Si Parla Ca]

dave-<< With a little research, I've figured out that it is a Chorus A-B unit. << Set in the B
position, the parallelogram slant is the same as modern Campy road units << Once this is done, the
overall geometry of the derailleur should be the same as a modern Campy unit, and it should index
with Ergopower shifters. Right?

Here is my question - which I cannot find a satisfactory answer on the web: Will this actually work?

"Maybe". No spring in the top pivot so keeping the top pulley in the prope place was tough. You
could probably mess with it and get it to work 'ok', but a modern 1991 or later works much better-

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
(303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"

 

[Qui Si Parla Ca]

Capt Bike-<< Your old Synchro Chorus derailer is certainly a lovely piece of jewelry, but as a
functioning derailer, it's way inferior to a $20 Shimano tourney or any other modern derailer.

Worked great with big barrell Record friction shifters.

I would say the indexing of the A-B Chorus doesn't exist but the duability, when used in friction,
would be much higher than any Tourney or any other $20 rder.

I guess I'm saying 'way inferior' are big words and assumes that 'click shifting' is 'way
superior'..which I don't agree with-better certainly but not 'the answer'-

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
(303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"

 

[Qui Si Parla Ca]

twoboogle-<< I'd agree about not using this with modern Ergo levers - but how will it work as a
friction shifter? I'm using an original Athena derailluer with old Campy retrofriction levers on the
downtube, and this combination shifts very nicely.

This one aas well as first gen Athena and CDA worked well in friction. If a 7s tho, needed to pull
the right lever 'way' back, why Campagnolo made a big barrell friction shifter for 8s.

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
(303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"

 

[David E. Belche]

Sheldon Brown <[email protected]> wrote in message
news:<[email protected]>...
>
> If I may digress, back in this era, Campagnolo also had the bright idea of making brake levers
> that could be set up either with traditional exposed cables or with "aero" (under the handlebar
> tape) table routing. Seemed like a good idea at the time, but the resulting overcompication
> obviated any advantage this might have had.
>

I actually had a set of these - as far as I know, all Campag metal aero levers retained this feature
right up until the end of production (the only Campag brake levers still made are the Record carbon
ones, a totally new design based on the current shape of Ergo lever), and certainly showed their age
a bit - unlike virtually all rival brands (right down to cheap & cheerful efforts like Shimano
300ex), they had no return springs, which made braking feel rather sluggish.

David E. Belcher

Dept. of Chemistry, University of York

 

[Sheldon Brown]

I Asserted

> Your old Synchro Chorus derailer is certainly a lovely piece of jewelry, but as a functioning
> derailer, it's way inferior to a $20 Shimano tourney or any other modern derailer.

Pietro Chisolmo demurred:

> Worked great with big barrell Record friction shifters.
>
> I would say the indexing of the A-B Chorus doesn't exist but the duability, when used in friction,
> would be much higher than any Tourney or any other $20 rder.

There are two kinds of "durability": wear resistance and crashworthiness. Since the Tourney is
made of steel, I'd give it the edge over the Athena in both regards. I've never seen either
model wear out.

> I guess I'm saying 'way inferior' are big words and assumes that 'click shifting' is 'way
> superior'..which I don't agree with-better certainly but not 'the answer'-

Actually "way" is a little word, and inferior is only medium size. ;-)

Is indexed shifting superior? I certainly believe it is for the rear, but that was not the point I
was making.

To make indexing work requires a certain level of design and workmanship, and resulting precision
movement of the derailer. While the workmanship of the Athena is lovely, the design of the cable
routing, and resulting short cable throw causes it to be too imprecise.

The only ways the Athena is superior to the Tourney are aesthetics and weight.

Sheldon "Tourney Is Better, Athena Is Prettier" Brown +----------------------------------------+
| When I am grown to man's estate | I shall be very proud and great, | And tell the other girls
| and boys | Not to meddle with my toys. | -R. L. Stevenson |
+----------------------------------------+ Harris Cyclery, West Newton, Massachusetts Phone
617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

 

[Sheldon Brown]

I wrote:

>>If I may digress, back in this era, Campagnolo also had the bright idea of making brake levers
>>that could be set up either with traditional exposed cables or with "aero" (under the handlebar
>>tape) table routing. Seemed like a good idea at the time, but the resulting overcompication
>>obviated any advantage this might have had.

David E. Belcher responded:

> I actually had a set of these - as far as I know, all Campag metal aero levers retained this
> feature right up until the end of production

It looks that way, but actually it isn't. I got fooled by this myself. I ordered in a pair for a
customer a couple of years ago, a customer who wanted to use them with the old-style exposed cable
routing. (I didn't stock them, 'cause I considered them ludicrously overpriced and not as good a the
$40 Shimano levers.)

When the levers arrived from the distributor, at first glance they _looked_ as if they could work
either way, but in fact they were "aero" only. The joker was that when Campagnolo changed the
levers, they didn't change the rubber hoods, so the _hoods_ were still the type that had the little
hole for the cable to come out the top!

I was amazed and appalled that Campagnolo would produce such a cheesy mono-buttocked setup. I lost a
lot of respect for the boys in Vicenza as a result of this.

Sheldon "Used To Worship At The Campagnolo Altar" Brown
+-------------------------------------------------------------+
| An editor is one who separates the wheat from the chaff | and prints the chaff. --Adlai
| Stevenson |
+-------------------------------------------------------------+ Harris Cyclery, West Newton,
Massachusetts Phone 617-244-9772 FAX 617-244-1041 http://harriscyclery.com Hard-to-find parts
shipped Worldwide http://captainbike.com http://sheldonbrown.com

 

[Mark Hickey]

Sheldon Brown <[email protected]> wrote:

>"Used To Worship At The Campagnolo Altar"

There's still time to repent, Sheldon.

Mark Hickey Habanero Cycles http://www.habcycles.com Home of the $695 ti frame