So I’ve had three of these fail in the same way now, as above, and I’m starting to wonder if it’s something I’m doing wrong, or if I’ve just been unlucky. To be fair to KMC they haven’t snapped catastrophically, I’ve just noticed a clicking and checked the link to discover it snapped on one side.

Two of them have been on the same MTB (XT running gear), and one on a road bike (105). They’re on KMC 10 speed chains, not worn or damaged (apart from the quicklink) probably with less than 500 miles on them each time. I don’t take the chains on and off for cleaning, but I do clean my bikes fairly well, and lube the chain regularly. The links were new on with each chain, not recycled from old ones. I don’t mash my gear changes particularly, the bikes aren’t prone to chainsuck or the like, and I’m not super heavy or super strong or particularly hard on my kit.

Any ideas? Am I doing something daft I’ve not thought of? Has anyone else had this happen to them repeatedly?

Err, no, no problems with mine.
But I’ll be checking for cracks…..

Yep

Had one go earlier in the year and a mate had one go as well. Luckily we had spares when riding

Replaced em with the gold ones off eBay for a few pence

Some are single use, some are reusable. It’s not that is it?

Yep, won’t use them anymore.
Thought it was just me as I’m a bit of a big gear masher. Gave one of mine to a mate who is much easier on chains than me and sure enough it failed. I’ve also had them rattle apart on rough descents. I always use shimano joining pins now with no failures.

KMC are reusable but there seems to be a dodgy batch of links

Think someone else had noted it on here a while ago

Some are single use, some are reusable. It’s not that is it?

Nope, KMC ones are meant to be multi-use. And I’m pretty sure that one up there hasn’t been undone since installation, the chain was new on earlier this year and I don’t think I’ve pulled it off since.

Sounds like it might not just be me then, good stuff. Time to go and check the other bikes’ chains…

There are definitely some KMC that are not re-usable…

http://www.kmcchain.eu/products-connectors-missing_links

…but if it’s never been undone that’s irrelevant.

Its not clear in your post,did they come with a new kmc chain or did you buy them separately ?

There are loads being sold on Aliexpress which could easily be fake.

That one there definitely came with a new chain. I’ve never bought stuff off Aliexpress, and I’m pretty sure that the others that snapped will have either been new with the chains or from CRC or Wiggle or somewhere in retail packaging, so I’m certain they’re not knock-offs.

There are definitely some KMC that are not re-usable…

Ah, didn’t know that, cheers. It’s definitely not one of the non-reusable ones though, you can’t really tell from the crappy phone pic, but it’s gold not silver. The others were the same.

Just excess power then 🙂

Yup, back to wipperman.

I’m pretty sure I read it on the box it came in that actually KMC 10sp links were OK to use 3 times. So annoyingly not really either multi use or single use… Never seen that before.

I had a KMC chain fail pretty badly on me a few months back, and I’m not a habitual destroyer of chains. Gone back to SRAM.

Been running 10 speed KMC missing links on two bikes for 2-3 years; no problems with mine.

sometimes, something will break, thats it,

Well, yeah, but if the same part from the same manufacturer breaks in the same way *three* times then I don’t think asking if there’s a connection is entirely unreasonable… 😉

i did 14,000km on a single KMC X10SL DLC – no issues, there is my experience

only time I’ve ever had a quick link break, is when it wasn’t fitted correctly and it broke within 200 metres (SRAM XX1 Chain)

Just to clear out some of the (I feel) confusion:
– all these links can only be “used” once – their lifetime equals that of the (new) chain they are attached to. Once the chain wears out, the link should be binned together with the chain.
– some links can be opened multiple times, some cannot; this is due to how they achieve the locking – in multi-use ones either the link itself gets wider and the ‘free’ pins get trapped in an indented area in the plates (SRAM), or there is a sort of labyrinth area which prevents the link from coming undone (Wippermann). The single-use ones rely on friction/deformation, if you do reuse them they will come undone easier when there is no tension on that particular area of the chain (i.e. bumps).

A link that has been installed correctly and has not been used beyond its lifetime should not fail in the manner reported by the OP.

A link that has been installed correctly and has not been used beyond its lifetime should not fail in the manner reported by the OP.

sometimes it does though, thats life,

speak to KMC

I can only relay personal experience. New KMC chain fitted. Fine for a couple of months . Chain fails at missing link when descending, fit spare purchased at the same time. Fine for a while, then fails at the link taking the rear mech and gear hanger with it. Throw chain in bin and fit shimano. Problem solved.

A link that has been installed correctly and has not been used beyond its lifetime should not fail in the manner reported by the OP.

Well three of mine have, so far, not to mention the various other people on here reporting the same thing.

speak to KMC

Nah. I’m not going to chase around after a couple of quid’s worth of bent metal. Like jamesoz, I’ll just buy someone else’s chains in future.

Bought a few 9 speed ones last year and they are equally as pap… Busted each one next ride it went on. Gave up and bought SRAM again…. KMC chains seem decent though but I guess they can’t do split links…

They say are non-reusable to cover their ar*ses against lawsuits.

I have re-used 10 and 11 speed quick links many times with issue.

When you attach and remove them with link pliers, do it slowly and gently so not to wear out the little tabs.

Run the chain through a rag every now and then to remove any grit that may make them wear prematurely.

As long as you dont keep removing them i.e taking the chain off the bike to clean it. They will be fine.

I never had a problem with the 9 speed ones, which is why I stuck with KMC when I went 10 speed. I’ve dug out a picture of the first one that failed on me too, for the record:

Exciting stuff, I know… 😉 This was taken on the ride it snapped on, hence the cack on the chain.

As long as you dont keep removing them i.e taking the chain off the bike to clean it. They will be fine.

As I keep saying, I don’t do that. I keep them clean with a bit of a hose down if it’s muddy (not a pressure washer) and a wipe with a rag, and I lube them every ride pretty much. And still, three of them have snapped on me now.

Never had a problem with mine & have been using them for years. Had an 11 speed one which bent, but didn’t break after a rough gear change.

Ten years of using KMC chains and doing at least 3,000 miles per year ( if not a lot more some years), and I’ve had one incident that might have been a quick link failure ( I never found one of the links so I’m not sure) and I had one incident where an outer plate fractured (but the creaking pointed it out in time for me to deal with it). I’ve done around 4,000 miles on 10 speed KMC chains and no incident yet.

But thanks for posting this up.

SRAM recalled a batch of around 24000 10s PowerLocks in 2009 with no injuries reported at the time of recall. If you think how many of this type of link from the different manufacturers are out there the problem is mercifully small

Been running 10 speed KMC missing links on two bikes for 2-3 years; no problems with mine

As he said !! 😉