Saturday, November 12, 2005

Campagnolo Syncro II shifters

In 1987, Campagnolo came out with an indexed shifting system they called 'Syncro'. It didn't work very well, and was generally tempermental. In 1989, they came out with an updated 'Syncro 2' that changed the spring arrangement, and updated to a higher capacity -- a large rear shifter "drum" diameter meant more cable could be taken up, to shift 7 speeds -- and possibly 8 as well.

I recently acquired more than a reasonable number of sets of Syncro 2 shifters. For a couple of reasons. First, I find them mechanically interesting -- and I'll discuss how they work shortly, with pics. Second, they're attractive -- same lines and design as the C-Record/Chorus/Croce d'Aune shifter bodies. Third, they pull enough cable to run with 8 or 9 speed in friction. Which brings us to number 4: they can be run in friction mode, but can also be easily modified to be a pure friction shifter. At which point, they're just as good as any other friction shifter.

Click any of the pictures for an larger version.

The left/front shifter is a standard friction shifter. I tried to get all fancy with something that looked like a parts explosion diagram.

The right/back shifter is entirely different, but easy to understand if you have pics.

The above is the inside of the lever. Note there are 2 small holes. 2 springs go in these holes, and create tension against....

the toothed boss collar, show above. Yellow is for 6 speeds. Count the indentations on each side, and you'll see 6. Other colors exist for 7 speed, and apparently there are 8 speed collars from the indexed barend shifters. I can't confirm that.

In the notches around the center of the collar, there are 2 cutouts. The large round metal piece above, to the left, has 2 cutouts matching the positioning of these notches. It also has the shaft around which the lever pivots. You'll see this in later pics. The other piece contains the retaining screw, and a spring loaded, knurled collar. It also has 2 teeth that go through the cutouts of the other piece, and engage the indentations in the collar.

The boss collar, with springs, inside of the lever.

The round metal piece, over the collar and springs, inside the lever.

Ok, so here's how the whole thing works. In the above picture, imagine the whole thing screwed together, with the notches, cutouts and teeth aligned as in the picture. The metal piece mates to the shift boss, and is held in a single position. The teeth of the knurled retention device are held in to place by this metal piece. The teeth hold the boss collar in one place as well. The shifter lever, and the 2 springs inside, are free to move. The springs have a shape that creates a sort of "pin" that rides in the grooves of the boss collar. Moving the lever moves the spring pins from one notch to the next.

By pulling the knurled portion of the retention thingy out, and aligning the teeth the way show above, the boss collar is released. Its spring loaded, so you can easily pull outward, and rotate it 90 degrees. The spring pins hold the collar in one place, and they pivot freely, as the teeth from the knurled part no longer keep it in place.

Sounds complex, but its pretty simple. Now, you can pull the knurled portion and use it as a combo index/friction system. That'd work, though indexing is tempermental. To convert them to pure friction, you can actually just remove the springs and optionally the boss collar -- the springs are all that is required to move. Removing the boss collar may create a little slop in the levers -- something I'd just as soon avoid. They're light enough that anyone who would consider running them would be hard pressed to justify caring. Anyhow, after conversion, they make nice large capacity friction shifters that don't need to be pulled obscenely far to take up 8 and more rear freewheel/cassette speeds.


Cracked Headtube said...

So, the Paper-mate pen is used to unlock Campy downtube shifters while the BIC pen is used to unlock Kryptonite Locks...ok, noted

Steve Barner said...

I was successful filing an additional notch on both sides of a Synchro II indexing collar and using the levers with an 8-spd Campy cassette. The lever came back a tad far, but it worked very well.

I wonder if you have any tricks for getting the collar and springs back in place. I found this quite difficult.

Jeremy said...

As a matter of fact, I do have a trick. Put both springs in. Take the round metal piece, and insert it from the backside of the shifter. You can use this to keep the collar centered as you insert it. You'll want to get one spring properly in place, and then use some thin tool, like a micro screwdriver, or a small allen wrench, to push the other spring back. Apply downward pressure on the collar, and it should pop in to place.

Unknown said...

Hi Jeremy,

do you konow if one can use 9 speed collars for current record bar end or down tube shifters in a synchro II shifter?


Jeremy said...

Unfortunately, Kay, you can't. The takeup barrel is larger in the 8 speed and later downtube shifters. As Steve said, it is possible to file an additional notch in to a collar to support 8 speeds -- you can see a picture of a collar someone did this to in my Syncro Rainbow post. In theory, you could try to file a ninth, but you'd be getting in to the area where the boss collar sits, and it'd probably cause some problems. In the best case scenario, you'd be pulling your levers WAY back.

Unknown said...

Hi Jeremy,

thanks for your fast reply. I browsed your blog and if I understood everything correctly, I could use a seven speed syncro 2 for 8 speed indexed shifting. For 9 speed, I had to find shifters of the 95+ generation and could change the index gear. Is this correct?


Anonymous said...

Hi Jeremy,

You don't know where I can get an exploded diagram on the assembly of these original Campagnolo Syncro shifters?

Link below:-

Thanks very much,


Jeremy said...

Hi Tony-
I've scanned in a parts explosion of the Syncro I shifter. You can see it here: I/SyncroI.jpg


Anonymous said...

Thanks very much for image.



Robert M said...

Hi Jeremy, would you know where I could buy a set of Syncro II shifters. I've been looking around but can't seem to find any.


Jeremy said...

Robert, drop me an email at blogs at tears for gears dot com and we can discuss.

Anonymous said...

I wish I was reding this before actualy buying. Anyway, my question is this, I am trying to set an athena index shifter with victory/trionphe (not sure what it is) rear der' and with shimano HG 7 speed cassett. No luck. according to the tables it seems o.k. What am I doing wrong? Also, what is "A" position and "B" position with the Chorus der'?
I am almost desperate with that.
Thank you.

Unknown said...

Hi, noticed you have a number of these levers.. Do you have 6V or 7V inserts you'd be willing to sell?

Unknown said...


Nice post on Syncro II shifters. I have trouble with the left shifter (friction for front derailleur). It not stays in place, when I pull it to move the chain to bigger chainring it comes back a little and so the front derailleur starts to rub the chain.

The left shifter in comparison to a Suntour Accushift Superbe Pro is an engineering disaster. I have never this kind of trouble with my Suntour.

Do you have any trick for that?

Thanks for the help.


Jeremy said...

First thing is to make sure you have all the various brass washers that I show in my pictures. If any are missing, you'll have problems. Make sure the wingnut is tightened down snuggly. Are your shifter bosses clean? Is there paint at the bottom of the threading for the wingnut screw? If there's anything that could keep the screw from seating fully, eliminate it!

Anonymous said...

I have a wish list for a few missing parts from my 1988 chorus group set. Could you set my in the right direction on how to find the parts?
1) rear derailler Pivot bolt (the main bolt)
2) one of those tiny springs from inside my sychro 2 sfifters

And my really long shot;

3) 180mm or 177mm crank arms

If you can help, please email me:

Unknown said...

Late for dinner one day, right hand shifter pops off! In the middle of a busy intersection! The lever remains attached to the cable, which in turn remains attached to the bike, but the spring and the bolt and presumably another part or two are nowhere to be found. The bike is a Bianchi Trofeo, and I'm pretty sure it's from 1995 or 1996...I'm assuming that the shifters aren't Record (they are curved, though they look similar to the ones in the post in other ways)...I've been chasing after parts on Ebay since, with no luck so far. Do you have a) advice? or b) spare shifter innards that I could buy from you? It seems unlikely that you'll ever see this or have time to respond, but given the depth of your knowledge of these things I thought I might hazard a note.

And thank you, in any case, for the wonderful bike geek blog!


Mike L said...

Hey Jeremy,

I'm trying to fix my old Bianchi. I've got a Campy 9 speed wheel and I can modify the index gear to add a notch, but will I need a 9 speed derailleur? I've still got my old 7 speed derailleur and if I modify the index gear, will I get enough travel?

wim-kesini said...

i just mounted the syncro II black 7v collar for my chorus 1988 (1st generation Chorus derailleur, in B position)on an 8 speed record hub/cassette.
it works all right, even without filing an extra notch. I simply adjusted one of the adjusting screws so that the derailleur snaps to the 8th cog. Only to see that there is maybe 3 mm between the derailleur and the spokes. Anyone any idea if this is a problem? is it dangerous? ao all right?
should i change the chorus for a athena?

Jeremy said...

There's a risk that under stress, it'll slide out of the 8th gear, since there's no notch to hold the shifter in place. Chances are it'll happen when you're climbing, and that will definitely suck.

3mm is pretty close. I'd want more space. Can you stick a spacer behind the 8th cog to give yourself a little more room?

elladaddy said...


Here's the index gear from 9s bar ends:

I have a question though. I'm trying to use them
as DTs. In an (probably ill-advised attempt) to
re-orient their position, I took them apart before
installing them on the DT. Now, after looking at the
index gear, I can't tell how to orient it.

Which notch is for 1st gear? The spacing between
teeth on the index gear are not uniform and I've read
that campy shifters pull more cable for certain gears
than others, so I'm assuming I can't just slide the
index gear into any position. But the burning
question is what position SHOULD I slide it into?

Thanks, Michael.

Salvatore said...
This comment has been removed by the author.
Salvatore said...


I've noticed on eBay and elsewhere that people refer to the 80s Chorus derailleur (with the A/B options) in the following way: Campagnolo C-Record Chorus/Croce D'Aune. I mean which is it: C-Record, Chorus or Croce D'Aune? I ask because the infamous Syncro 2 compatibility chart clearly distinguishes them as separate or three different rear derailleurs. Is the Chorus the one with the A/B options and the Croce d'Aune (which is what i believe you use with your yellow S2 insert) the one with the horizontal rod? Also, do you know where one can find a photo of each of the derailleurs that run across the top of the Syncro 2 compatibility chart?


Anonymous said...

This blog was very helpful and I've come across it a bit late, but I've got 2 sets of synchro shifters, one with a 6sp insert and another with an 8sp (red) insert. I took the 8sp all apart and was wondering how I can run this shifter in friction only. Do I need to remove the indented ring on the inside for it to work in friction? If I remove it, there is too much movement in the lever (side-to-side) for it to work properly.

I've currently got a pair of Simplex retro friction shifters on a vintage frame which I absolutely love but can't use for anything more than 7sp since the amount of cable pull on the shifter isn't enough to go through all 8 gears.

Basically I want to stick to DT shifters (preferrably friction only) on an 8sp cassette.

Tyler said...

I'm doing a rebuild and I've taken everything off except a seized seat post and this damn shifter.
I can't seem to get the (large) "Round Metal Piece" out. This should just slip out?
Any advice would be appreciated.

Steve Barner said...

Nothing like keeping an 11 year old post alive! Still, there are several unanswered questions here. Salvatore asked about the different late-1980s derailleur models. It's easy to find info on these and, yes, they were all distinctly different models, very easy to differentiate. eBay sellers are notorious for sounding knowledgeable when they in fact know nothing at all. The different rear mechs took different right shifter inserts, based primarily on the number of cogs.

Michael asked about the direction to install the insert and the answer is that you can't put it in backwards and still get the outer piece with the knurled knob in place. The notches in the sides of the insert have to face out. An Anonymous poster asked about running a Syncro II right shifter in friction mode. With most of these, you pull the knurled ring out and give it a turn. I never liked the feel of these in friction mode when compared to a regular friction shifter, which seemed more positive and with less slop. Later versions had no friction option.

Friction-only shifters that loosen up do so because of slop between the outer nylon bushing and the flats of the shifter boss, in addition to problems with the thumbscrew threads. There are several reasons for this, including undersized bosses (very hard to correct) and worn inserts (just replace them, though parts are now hard to find). The first thing to try is to clean the threads with acetone or other suitable solvent that leaves no residue and put some blue Loctite on the threads. Be sure to adjust the tension the way you want it to stay, and then don't move it for a day, giving the Loctite time to setup.

Tyler asked more recently how to get the round metal piece out. I've had this happen and don't have a great answer. Usually it practically falls out when you have the screw completely out of its thread, but sometimes they seem to be stuck on the stud. Be careful to not lose parts when it finally pops loose!

The Simplex shifters had a cable barrel diameter of 14mm, while the Campy friction, Syncro, and Sycro II shifters had a diameter of 16mm. This is why the Simplex levers have to move farther to shift the same number of cogs. It makes them a tad easier to fine-tune the derailleur, but also makes the swing a bit far for 8-spd rear or triple front setups. The later Campy 8-speed setups went to a much larger barrel diameter of almost 26mm and there is no compatibility between them and the earlier ones. If you have a Campy derailleur of the Ergoshift era, after Suntour's Slant-Parallelogram patents expired, that's the shifter you need.

Anonymous said...

thanks for this article! my left synchro shifter is slipping when my chain is on 53 crank. I will see if I'm missing some innards.

Moshin said...

Thank you so much for this amazing article. I just got a X4 randomly, and am going to try to fix her up. I think these are the shifters I need, but curious, can someone confirm that these shifters can take on 8-9-10 speeds? I have 130mm space in between my rear dropouts. I dont want to get hamstrung for purchasing the wrong shifters.


Salvatore said...

Moshin - If you purchase the 8-speed Syncro II shifters, which is slightly different the 5, 6, 7 speed shifters, you can go to 8-speed. The 8-speed comes in a shorter, elongated, rectangular box (as opposed to the Syncro II 5, 6, 7 which is more a square-shaped box). With the 8-speed, you can go up to 9-speed in friction mode only. Note: you must have the correct model of derailleur, freewheel and chain for them to work properly. There's a chart in circulation that tells you which components allow the shifter to work smoothly.

Unknown said...

Salvatore, Do you happen tho know where one might find that chart that tells you which components allow the shifter to work smoothly?

Salvatore said...

trying to post the images here. any suggestions? doesn't seem to allow me to upload.

Moshin said...

Hello! Thanks for this wonderful post, and all your helpful engagement.

I recently stumbled upon a cheap frame that ended up being a Bianchi TSX. Later I bought an old cracked bianchi and took the group set off of it for the TSX.

THe reason I am writing you, is your article has been super helpful to me, but i Have one issue I am hoping you can help with.

My left/front Synchro shifter will not maintain its position on the big ring. When I let go of hte lever it goes back to where it started. I understand that the screw provides tension, and this is likely too loose, or bushings / washers are missing. I am comparing to your images and it appears I have everything, however I am wondering if the white washer nearest to the frame is "thinner" than the one in your image.

The tension / mount screw seems to be loose. I am sort of at an impasse as a junior ambitious mechanic. Do you have any advice? A place I can get this part if my suspicions are correct?

Thanks in advance for all that you do !

JohnBoy said...

Hello, THANK YOU for the great post about Synchro gears. I have just fitted one together without the tool.

Firstly, just put one spring in place and then the gear cog alongside it in the correct position, as you show previously.

Secondly, put the second spring into the correct notch and then manipulate the spring into it's 'hole' position.

All done with minimum fuss and no need for a VERY expensive tool.

If this helps one person a lot of stress, then I'll be happy :)

JohnBoy said...

Alleviate a lot stress......typo!

simon lumsdon said...

Just to resurrect this thread again, I am trying to use the Synchro II campag record downtube shifters with an Athena 11 speed setup. Was assured the shifters i purchased on ebay would work with 11 but have sneaking suspicion that are for 10 speed (they were the bar end varient which i have altered for down tube fitment). Looks like they are pulling too much cable for each increment.
1) Is there such a thing as an 11 speed insert for these shifters?
2) Has anyone got this to work
3) could i bodge the rear mech by extending the clamp to reduce the cable leverage/pull?

I like these shifters and have used them over the years on 6/7/8 & 10 speed setups and "think" i might have used a similar bar end 11 speed setup in the past but just cant remember :-(

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