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]

Originally Posted by 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?

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/mas...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]

Originally Posted by Lionel

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]

Originally Posted by mcteague

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]

Originally Posted by fignon's barber

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]

Originally Posted by 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?

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

Tim