Campy 12s chain snapped

[mcteague]

While climbing a hill, and not pushing all that hard, my bike suddenly veered left but managed to stay up. Looked down to see the chain trailing behind me. At first I figured it broke at the KMC 12s quick link but it seems to be right behind the link. Any ideas on how I may have caused this or is it just one of those things? The fact that the quick link was involved makes me wonder if I should stick with peening.

Tim

[Blown Reek]

Was the link that broke the one side that was shortened, or was it the side that wasn't shortened?

I have the exact same setup on one of my bikes, and after years and miles on Campy chains with Wippermann links, I have had zero problem.

[AngryScientist]

oof, that aint good. how many miles would you say were on this chain?

glad you were able to keep upright!

[mulp]

Glad your safe!

From the looks of it, I would be suspect if the quick link were not involved. It is possible that either the quick link was too tight and it was wearing away the metal beneath it or it was too lose and some coarse crud got in and starting wearing it out. The fact it broke so cleanly indicates that the integrity in that link was compromised more so than the other parts of the chain. At least thats my read on it.

[Buzz]

I’ve noticed as we have gone from 9 speed to 10, 11 and 12 that the KMC chain link has become more finicky in installation and requires a tool to properly install. I had to toss a new KMC link a couple of years ago because it just would not install properly. Another KMC link went right on without a problem. But otherwise like others have had this set up for years and never had a problem on the road. Perhaps the KMC link got hung up just enough to stress the next link?

[Mark McM]

I’ve noticed as we have gone from 9 speed to 10, 11 and 12 that the KMC chain link has become more finicky in installation and requires a tool to properly install. I had to toss a new KMC link a couple of years ago because it just would not install properly. Another KMC link went right on without a problem. But otherwise like others have had this set up for years and never had a problem on the road. Perhaps the KMC link got hung up just enough to stress the next link?

What tool is required to install a KMC quick link? I've used 9spd, 10spd and 11spd KMC chains, and I've never needed a tool to install the chain (other than a chain rivet tool to shorten the chain). I just engage the quick link (squeezing the plates together by hand), rotated the cranks until the quicklink was on the top run of chain, and then applied force to the pedal until the quicklink rivets locked into their slots.

[Dave]

The KMC 12 quick link requires no tool to install. It is a relatively loose fit, however.

A SRAM eagle 12 speed link fits better and a AXS 12 link is too tight.

To use a quick link, the original virgin outer plates have to be removed. That should have nothing to do with the failure. The inner plates are all the same.

[Buzz]

Not “required”but makes installation and removal very easy. Park tool mlp 1.2

https://www.parktool.com/product/master-link-pliers-mlp-1-2

[mcteague]

The KMC link does not really require a tool to install but I did use a Park MLP-1.2 and the link installed easily. Thinking back on the original install; I used the new Park CT-4.3 chain tool with 12s peening feature. When I used it the tool pin broke when peening the Campy pin. I suspect I may have caused some damage to the hole in the connecting chain part as that is where it broke. I gave up on trying to peen the thing and bought the KMC link as I have had good luck with them on 10 and 11 speed chains.

Also, not sure how much mileage it has, maybe 2k miles at most.

Tim

[Lionel]

Always use the proper campy tool to join a campy chain. No quick link.

[mcteague]

Always use the proper campy tool to join a campy chain. No quick link.

Yeah, well, for a tool I only will use once every year or two the Campy tool just costs too much. So, either I find a shop that speaks Campagnolo (especially 12s) and have them peen it or keep using the link.

Tim

[fignon's barber]

Yeah, well, for a tool I only will use once every year or two the Campy tool just costs too much. So, either I find a shop that speaks Campagnolo (especially 12s) and have them peen it or keep using the link.

Tim


I think his point is to always join the chain permanently, as is the preferred method at Campagnolo. The only down side is you have to clean the chain while its on the bike, but you get more piece of mind.

[mcteague]

I think his point is to always join the chain permanently, as is the preferred method at Campagnolo. The only down side is you have to clean the chain while its on the bike, but you get more piece of mind.

Understood. Still, the Campy tool is $150-200! For a rarely used tool that is too much for me. When I got the Record parts the local Campy specialist, who mostly does service rather than selling, did not have the 12 speed stuff in yet. I may try him again.

Tim

[ultraman6970]

Interesting and terrifying at the same time.

One thing for sure, the kmc missing link standed w/o any problems. Time to go campagnolo chains with KMC link?

[mcteague]

Interesting and terrifying at the same time.

One thing for sure, the kmc missing link standed w/o any problems. Time to go campagnolo chains with KMC link?

That’s what I used, Campy R12 chain and KMC 12s link.

Tim

[mulp]

Just because the KMC missing link didn't break doesnt mean it didnt contribute to the chain breaking...at least theoretically.

Interesting and terrifying at the same time.

One thing for sure, the kmc missing link standed w/o any problems. Time to go campagnolo chains with KMC link?

[mcteague]

Here is a better shot of the broken link. My guess is I may have damaged it when I first tried to break the chain with the Park tool. I recall it took a lot of force so I backed off, re-centered the pin and was then able to break the chain. It just may have taken months of riding before it finally gave way.

Tim

[chiasticon]

Understood. Still, the Campy tool is $150-200! For a rarely used tool that is too much for me.I know the Park Master chain tool is said to work with Campy 11, I'm not sure about 12 though. but I guess if Campy didn't update their official tool when they released 12 speed, it should.

personally if I were considering getting the Campy chain tool, I'd get the Abbey one instead: https://www.abbeybiketools.com/collections/new-additions/products/decade-chain-tool

but same deal there: not cheap.

[mcteague]

I know the Park Master chain tool is said to work with Campy 11, I'm not sure about 12 though. but I guess if Campy didn't update their official tool when they released 12 speed, it should.

personally if I were considering getting the Campy chain tool, I'd get the Abbey one instead: https://www.abbeybiketools.com/collections/new-additions/products/decade-chain-tool

but same deal there: not cheap.

The Park CT-4.3 professes to work with Campy 12. When the pin broke it appeared to be basic, pot metal. I know they have replacement pins but I lost confidence in it and returned the tool.

https://www.parktool.com/product/master-chain-tool-with-peening-anvil-ct-4-3?category=Chain

Tim

[oldpotatoe]

That’s what I used, Campy R12 chain and KMC 12s link.

Tim

Considering that where the inner link broke seems right at the KMC link plate..can't help but think wear/rubbing/interference with the link caused this.
Any chain noise, intermittent clicking before this happened?

[Dave]

Jenson has a 4 pack of sram eagle 12 speed links for $13. They have the best fit for the campy 12 chain. The cheap park ct-3.3 will work fine to remove excess links. If the joining pin is never used, just remove the links from the end with the virgin outer plates.

[thwart]

Thinking back on the original install; I used the new Park CT-4.3 chain tool with 12s peening feature. When I used it the tool pin broke when peening the Campy pin. I suspect I may have caused some damage to the hole in the connecting chain part as that is where it broke. I gave up on trying to peen the thing and bought the KMC link...

Reassuring. This seems to explain the failure (at least if I read this right).

[Burnette]

While climbing a hill, and not pushing all that hard, my bike suddenly veered left but managed to stay up. Looked down to see the chain trailing behind me. At first I figured it broke at the KMC 12s quick link but it seems to be right behind the link. Any ideas on how I may have caused this or is it just one of those things? The fact that the quick link was involved makes me wonder if I should stick with peening.

Tim

I was always told that the weakest get dropped on the climbs, so the hill culled the herd from the bike!

But seriously, glad you're ok. If you were standing and/or were going up a 15% grade that could have ended badly.

As far as the expensive tool, dang, if you only had one bike with Campy it would be a push to fork over that much for a tool you would rarely use. That tool sounds like a pool, better to know someone who has one than to own one :)

[oldpotatoe]

I know the Park Master chain tool is said to work with Campy 11, I'm not sure about 12 though. but I guess if Campy didn't update their official tool when they released 12 speed, it should.

personally if I were considering getting the Campy chain tool, I'd get the Abbey one instead: https://www.abbeybiketools.com/collections/new-additions/products/decade-chain-tool

but same deal there: not cheap.

With the little wound up wire gizmo on the Campag that holds the link flat when you push in the pin and then peen, is essential, IMHO..PLUS the Campag tool is about the same $ as the abbey tool..abbey tool is nice, but I've had 10 and 11s(now 12s) Campag tools and they are really sweet...

[ultraman6970]

And the campagnolo chain failed?? scary... IMO you cant blame kmc for the problem, well could be a manufacturing issue with that link. The other detail is that many guys are using the campy chain with the kmc link w/o any problem.

KMC chain combo from now on?



That’s what I used, Campy R12 chain and KMC 12s link.

Tim

[ultraman6970]

But at the same time, campagnolo stamps zillions of those, and if the OP got lucky he might have gotten the 1 in a million link that is not right... other people use the same combination too... so who knows, a weird accident?

Good think he did well, because that accident could have finish really bad...

Just because the KMC missing link didn't break doesnt mean it didnt contribute to the chain breaking...at least theoretically.

[mcteague]

Thanks everyone for chiming in. As I mentioned I think the fault lies with me. When I first tried to break the new R12 chain, to remove the extra links, the Park pin started to bend a bit. It looked centered with the chain pin but I backed it off and tried again and was able to push the pin out. When I tried to install the special peening pin the Park tool broke. My guess is that when I first tried to break the chain the tool was not perfectly centered and may have caused the underlying damage that took months of riding before it finally gave way.

For now, I removed one link and re-used the KMC link (I know, single use) and rode again today. I still think I should get a new Chorus chain and have it properly peened.

Tim

[cmbicycles]

Yeah, well, for a tool I only will use once every year or two the Campy tool just costs too much. So, either I find a shop that speaks Campagnolo (especially 12s) and have them peen it or keep using the link.

Tim

Campy tools are nice, and nice often comes with a higher price tag. I've always used a Pedros Tutto chain tool for 11s campy, its around $50-60 +/-. Breaks the chain, peens the new pin, and Pedros says works for 12s too.