Question about KMC chains with "quick link".

I fitted a KMC chain and it's broken twice, presumably where I shortened, then re-joined the chain with a chain tool. The chain came with a quick link, but I didn't use it and instead I just used a chain breaker tool as normal.

Is this a no-no with KMC chains, should you always use the special link?

Comparing the chain to a Campagnolo chain I have, the KMC seems lighter, with thinner side plates, and the pins don't sit as proud of the side plates. The Campag chain pins are also flat on the end, whereas the KMC chain pins have a dimple in the end, they are also much harder to push out than the Campag pins, which makes me wonder whether you shouldn't push them out and then back in again, but only out, to shorten the chain, then use the special link.

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Interesting, I have a KMC chain on my C16-r with "quick link" in use but it has snapped once and i removed a link and re-joined it but it hasn't been the same since.
I have put a SRAM P870 on my Stumpy and its been fine. I wouldn't go back to KMC now.

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I have nothing but good things to say about kmc chains but you should always use the quick link!

This ^^^^^^^^^^^^^^^

Have them on all my bikes, and some have a few quick links in their chains to add in short sections.

I now know to measure twice, cut once.

I do have had this issue with quick link chains! Will pay attention from now on.

Quick link my arse by the way!

Modern chains use mushroomed/peened head pins, you can't reuse them. Once you've pushed the head of the pin through the sideplate you'll do one of two things.
1) take the mushrooming off the pin.
2) deform the hole in the side plate.

Both of these mean that the fit of the pin into the hole isn't strong enough anymore. Hence the oversize shimano joining pin.

If you do rejoin a chain using the old pin, it might fail immediately, or it might do 1000 miles, then snap.
All 9, 10 and 11 speeds will be peened, a good few 8s might be too, but I've not had or fitted anything 8 speed for ~15 years........

Just use the quick links and fit them properly (some are directional)

I either use kmc or Sram chains, always use the quick link, and have never had one snap on me.
In the past I've also used a regular chain tool to add a few links back in but never encountered any issues, maybe I was just lucky.
Imo the quick links are mega handy for chain removal & cleaning, there is a "knack" to undoing them by hand, but there's also tools you can get that make it a doddle.
As for lube, if it's dry I use dry lube, if it's wet I use wet lube. Anything is better than no lube at aall!

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OK, lesson learned, I'll stick with Campagnolo from now on.

Their 9 speed chains don't have quick links or special pins, they last for ages too:



Although, I don't remember having any issues with an SRAM 9 speed chain, that came with a quick link, that I didn't use. The problem wasn't it coming apart, but that was that it wore out so quickly, I reckon I got less than 500 miles out of it.

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Kmc have a guarantee on the chains, check it out if you are not satisfied.

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Yeah but I doubt the guarantee covers rejoining with same pin

What he said about peened pins
I have done it on shims I chain but took a round needle file to put a tiny chamfer round the hole on the inside of the plate to encourage the flattened end of the pin to go into the link. Not recommended but needs must