Hello all,

are campy jockey wheels directional and or Top/Bottom specific? I have a situation where I believe the chain is dragging on the lower jockey wheel cage. This happens when I am in the upper range of the cassette. I do not think it's out of alignment, image evidence from the internet seems to show the red hub on the bottom and the raw one on the top, though I do have another Campy set up where this is flipped and no issues. I thought maybe the lower red jockey wheel is directional and that the writing should face the outside? I am unsure if there is writing on both sides or if those hub caps could have been separately flipped. Maybe it is immaterial and the issue is totally something else?





any help appreciated

thanks in advance.

Jeff

Yes & yes. The upper and lower are different, and the lower is directional. It should be marked on the wheel next to the hub.

Yes, they are but you appear to have them correctly assembled.

The upper (guide) pulley is labelled as such and is unidirerectional. The lower (idler) pulley is labelled and has a direction of rotation arrow marked but in any case, the moulded-in writing is on the "visible side" when looked at from the gear side.

If the chain is touching the inside of the cage, it may be that the vertical alignment of the hanger is good but the horizontal alignment is off - this is quite common as a lot of mechanics hesitate to adjust it, it can be a bit awkward to get it right whilst maintaining vertical alignment ...

It may also be that the o-rings in the top pivot bolt assembly, that allow a small amount of chain-tension driven alignment of the RD, are worn or degraded. Depending on the RD version, replacement of these o-rings may be a shop / competent home mechanic job, or a Campagnolo Service Centre job.

If the RD has an allen key-type steel upper pivot bolt, that's a shop / competent home mechanic job as the TPB is retained by a circlip. You just need to re-tension the upper spring on reassembly which is easy enough if you know the trick.

If it's Torx though, that's a SC job as the bolt removal is either by drilling out or if you are lucky, it can be taken out with a Campag Vicenza SC made tool (not sold to the trade at large) also used for fitting. The Service Instruction required that the bolt is replaced on removal / refitting anyway and the bolt should not be available to the public (although we have seen it being sold), since it requires the aforementioned tool for fitting.

We have, in extremis, refitted an original bolt but do not recommend doing so.

After fitting, the range of movement allowed by the o-rings needs to be checked for correct RD function, which needs a jig that the SCs usually have to make up themselves, using a surface plate and a boss screwed into it, on which to mount the RD.

In rare cases, if the o-rings have degraded badly and / or the sleeve that they run on has worn, oversize o-rings (non Campag part) are needed.

Really appreciate the reply, I did remove and double check the Jockey Wheels as I had to clean my drive train any away. They were installed correctly as you mentioned. This RD is the torx bolt type, so I'd have to see a dealer if the o-rings are worn. Is there a relative way to tell if those o-rings are shot by moving the RD say with some rocking motion by hand? -guessing like half MM of play is probably good, more is probably not so good?

You also mentioned "horizontal alignment" - does this mean bending of the hanger? It is a steel frame, so there is no hanger, the mount is the actual dropout itself. I was not aware of any horizontal adjustment on the RD itself so I am guessing cold bending of the drop out would be needed if this were the case?

Again appreciate the reply,

Jeff

Broadly yes, we use the vertical distance from end of the bolt that secures the jockey cage to the lower pivot as the datum, to the surface table at 0, 120 and 240 degrees of rotation around the boss that is vertical relative to the table. Max variation allowed is +/-0.25mm. Very hard to quantify any other way. A "waggle test" isn't really reliable enough.

Yes. Lots of mechs don't like adjusting the fore-aft true as it throws the up-down alignment out - but the face of the hanger that the RD bolts up against does need to be, within boundaries, co-planar with the sprockets / wheel.

The problem is the repeated bending of the hanger to adjust both "x" and "y" alignment. This can weaken or, in extreme cases, cause failure in the hanger. There's a trick to doing both with a minimal amount of adjustment that a lot of mechanics never quite acquire!

No problem!