Strange Campagnolo Chorus 11sp Issue
 

So I purchased a used 11sp Chorus group about a 6 months ago, but only recently got it installed and put to use. First impressions were great, but then I noticed the shifting seemed to be getting a little bit rougher.

When I did a quick inspection, I noticed a small pin starting to come out of place (see photo). This pin doesn't have a part number in the usual Campagnolo spare parts catalog, as I assume it isn't meant to be removed and/or replaced.

Pushing on it with just normal finger pressure slid it right back down into place, but it started coming out again after just 10 miles or so. My next idea was to push it in with a small probe, and really try to seat it as firmly as possible (light taps with a screwdriver). But the result was the same: it stared popping out again after just a few miles. Because it is so easy to push back into place (very little resistance), I even tried putting a small piece of tape over it, but it pushed the tape up as expected.

Has anyone experienced something like this before? Any ideas on keeping it down? The first time I noticed it, it was probably another few MM further out than shown in the picture below, and my concern is that it would work its way far enough out that the joint would become displaced. I have inspected similar 11sp units from Campagnolo, and all of them have rock solid pins, so I have no idea how this ever worked itself loose (although I did buy it used, so many the previous owner was messing around with it).

(I know it's hard to see in the picture, but the circled pin isn't sitting flush)
https://cimg4.ibsrv.net/gimg/bikefor...58fa3e58f6.jpg

Which fuzzy pixel is the pin? Maybe glue it in place.

Yeah, sorry about that picture. Below is a diagram that illustrates it better. That's not the same model derailleur that I have, but that pin is the same (and as you can see, doesn't have a part number). It is working it's way out toward the top of the derailleur when mounted on the bike.

I thought about gluing it, but wasn't sure if it needed to be free to pivot or something. I actually tried throwing a little blue loctite on it, and so far it has stayed in place (fingers crossed that it does). I just don't understand how it became loose in the first place. https://cimg0.ibsrv.net/gimg/bikefor...3cbfa2ec68.jpg

You better take the RD apart and fix it right, or you may end up stranded on a ride. I have that rivet on my RD and it appears to anchor the end of the torsion spring. You might be able to replace it with a very small screw, but this is considered a non repairable item.

Why is this such a frequent occurrence? You'd think that someone posting a pic would at least make it legible but so often some blurry pic is posted instead. How long does it take to get a second shot in?

On my Record derailleur, it appears to be a long pin that holds a spring. If the side you are indicating is like mine, it is a hollow pin, secured by knurling on one side, and a flare on the other side:

https://cimg7.ibsrv.net/gimg/bikefor...40d41c7d59.jpg


https://cimg0.ibsrv.net/gimg/bikefor...cba74e82ff.jpg

I don't know what's on the other side of your pin.
Looking at the image, it looks like there is a small collar holding the pin in.
If it's the same hollow type pin, perhaps somehow the flare became crushed or the collar completely fell off. If anything is showing, you might try expanding it using a center hole punch chisel and tapping lightly to flare the end.
JB Weld both sides? It doesn't appear to be a moving part.
Actually it's not so small that you couldn't tap it and as suggested, install a machine screw.
Hope this helps.

Update: so far the blue loctite has been holding it in place, and yesterday I did a fair bit of riding on some very rough roads with a ton of shifting.

If this doesn't hold, I'm pretty sure some red loctite will do the trick

It's the pin that runs all the way through the torsion spring, from top to bottom (see jideta's post for better pics and details). Luckily I'm in the big apple, so "stranded" usually just means a walk to the nearest subway station. That said, I definitely don't want it to fail as I'm sure the damage to the derailleur and bike would be significant, and so I'm monitoring it all the time.

Hey, I apologized, didn't I? And you know how some phones just don't want to focus on the tiny little pin that you want them to focus on, right? And yeah, I'm tapping the screen and whatnot to try and get it to cooperate.

Yes, this is the exact pin. Mine doesn't have a collar on the top, however, and I've compared it to a Record RD from that same generation, and that one doesn't have it either. As far as the knurling on the bottom, I can't really see it, and that might be part of the problem. I don't know if it's missing, worn away, or just not engaged far enough for me to see it.

JB Weld did come to mind for me, but I thought I would try loctite first (and so far, so good). I did also try tapping it a little with a punch, to do exactly what you said, (fully seat it and widen the collar at the top), but strangely that didn't work at all. Maybe I was just too gentle.

I'd definitely prefer not to have to tap it or insert a screw of any kind, and I'm sure that if the existing pin is removed (or works it's way out), re-assembling that part with the spring under tension is probably a pretty annoying 4 hand job.