Clattering noise on some cogs with Record 12 mechanical and Cervelo S5.
 

Well, I bought the frameset like I usually do and moved the Record 12 mechanical group from my old Look 675 frame over to this. I had a local lbs do the assembly for me.

The problem I am having is that (mainly on the big ring) the chain makes this clacking noise but only on certain gears. Only yesterday I took it to a different lbs and we checked the hanger (it was a little bent from the factory), made sure the cassette lock ring was properly torqued, the limit screws were set properly and played with cable tension forever.

I noticed that when it was originally assembled, an additional extension bracket was installed between the hanger and the RD itself. When we removed it it became impossible to shift onto the smallest cog. This bracket is 6.45mm wide by the way and I think it works as a spacer, never seen anything like it before but then I’m no mechanic.

We put the bracket back and every shift is perfect but the clacking noise is terrible and it’s worse on the larger cogs. It also baffles me because it’s there on say the 19 but not the 18 and it comes back louder a cog or two down the cassette. Everything is very low mileage on this group; I ordered a new chain and ultralinks last night in case it’s the chain because it does have two of those sram quicklinks.

Is there anything special about installing Campy 12 speed on these frames? It’s a second gen S5 in case this helps at all. I don’t even want to ride the bike because of this noise 😌

Why does the chain have 2 SRAM quicklinks? How worn is it? Seeing that it is a Record 12 speed setup, it can't be all that old. Did you have to add links for the new bike? If so, a new chain from the outset would have been a better choice. Some frames transmit noise much more than others. Some monocoque frames can really make a drivetrain sound a lot louder.

It had one quick link before taking apart the other bike and when they broke the chain, the mechanic apparently didn't realize there was a quick link in place. Then the other place ended up adding another ql....crazy, I know. I did order a new chain and an ultra link this time but even then, why does it make more noise on some cogs than others? The cassette is also brand new.

Is it different if you are shifting from hi to low as opposed to low to hi? Everything is Campy? Hub, cassette, shifter, DR, chain?

Well, the only unanswered question is how many km(miles) on the original chain and also which chainring/cassette combinations you prefer to ride in. Just asking questions hoping to jog you into finding a solution. Bye the way, the so called mechanic who broke the expensive chain without a careful examination was an idiot if the goal was to reuse the chain

Yes, I actually learned last week that he was fired. This whole chain/cassette combo had really low mileage since I hadn’t been riding much, only put about 350 mikes this January. I’m staying between the 16-23 cogs most of the time in the big ring.

The only time I had random racket on some cogs and not others, my lock ring was not fully torqued. But you said you already checked that.

If you put it on one of the noisy cogs and then look from behind the bike, how does the derailleur alignment look? Is it off to either side slightly or directly under the engaged cog? If off, which side is it off towards? If you then put it on a different noisy cog, is it off the same direction?

That is a small consolation considering that he cut your chain up and installed a second unneeded quicklink. At a minimum, the shop should properly install a new chain, as long as they can find someone who knows how to install a Campagnlo 12 speed chain

Let me check for that...

Here are a couple of pics; the chain is noticeably less noisy now that I used Chain-L on it but it’s still there. These are the two loudest cogs.


https://cimg5.ibsrv.net/gimg/bikefor...237560f75.jpeg
https://cimg6.ibsrv.net/gimg/bikefor...ea9788d60.jpeg

I really cannot tell if there’s anything wrong, maybe a pair of sharper eyes will spot something.

What size is your cassette? Is your largest cog bigger than a 30? I’m trying to figure out why you need that hanger extension. Based on your description of the inept mechanic, I’m not convinced he knew what he was doing when your bike was originally built up. There should be no reason it would not shift to the smallest cog without that hanger extension. I encourage you to find the official Campagnolo YouTube channel and take a look at their install videos. They have the same video in multiple languages, so find the English version and watch it.

The hanger extension in the picture looks like a direct mount adapter, which Shimano derailleurs also have. It's required if your bike doesn't have a direct mount hanger, which most road bikes don't.

I think I can see it in this picture from Campagnolo's website.

My last "clatter in some gears but not others" was when I broke the Dura Ace cluster (some of the gears were triples, riveted, and the thing broke at the rivets) climbing a hill*. Something to check, anyway. Good luck.

*Not bragging, as in "look at me, I broke a Dura Ace cluster!" More like "Gee, I weigh a lot more than I did when I was 20", and "Gee, Shimano kind of over-engineered that cluster for weight savings." They've since redesigned it.

Update: I got a new Record chain installed, this time using the included ultralink chain pin. $47 shipped and worth every penny, considering that the standalone ultralink sells for 12-14 bucks. The noise is gone and I have a nice, quiet bike again.

I don’t know if this is an issue with quick links but from now on I will only use these Campy pins. Ymmv. Thanks to all that replied!

I've been using campy for 25 years and 12 speed since July of 2019. I have the Campy chain tool and use the pin for initial installation, but when I remove the chain for cleaning, I remove the joining pin and two outer plates to use a SRAM eagle 12 link for joining the chain. It will not cause a noise problem. I've also used a SRAM AXS 12 chain with no problem. The axs quick link will not work with a campy chain.

Yeah you think you had an 11 speed quick link on there?

You may be onto something but I guess I won’t ever know; I had them toss the old chain when I went to yet another shop that seemed competent for a change.