[Closed] KMC SL Chain snapped - recommend me another

ive run these for 4 years and never had a chain snap, setup maybe to short or bad shifting?

sorry not to sound like a 'its your fault' type comment, but my chains have been put through some mileage and wear/tear in the peak all year round and never suffered from snappage

they wear out eventually but not had any other issues

As above I have found kmc far stronger than sram or shimano. As a habitual chain breaker due to shifting under power I've broken one kmc chain and it took some middle ring teeth with it busted numerous others

Chains don’t snap as a result of general wear – you would get slipping and shifting issues before it got to the point where it snaps.

Snapping a chain would be some combination of damage, heavy handed riding or some kind of mechanical. Something must be wrong. Does it keep snapping in the same place? Could they be dodgy chains.

Disappointed with kmc magic link, Pita. Never had problems with SRAM/wipperman. My chain of choice is wipperman connex. The last one went on for ages.

I've used KMC, the SL version, then L then the cheap 10.93. It seems to me that the less you pay the longer they last. Unless you're really looking save every gram I'd go with a more robust solid link chain like the 10.93.

On another note, I'm failing to see any real advantage to the missing link, other than it's easier to get your chain off should you need to. KMC say you should fit a new missing link once you've undone it 3 times as they wear and become loose. You still need to carry a chain tool around in order to fix a broken chain anyway, plus missing links are over twice the price of shimano pins.

As others have said, I would imagine something is wrong if you are snapping chains.

I wont put another 9 speed KMC chain on a bike, the quick links can and have fallen apart with vibration and you can't join the chain without them, well you can use a chain splitter but it wont last long. Utter crap.

I've used the old large to large ring plus 2 links when measuring the chain.
I've done about 500 miles on one of them and as I said it's not stretched to 75% yet.
I'm running on 2x10 so maybe i spend too much time in the 38 up front and 36 on rear causing too strain on the links.
On one of the chains I'd noticed the links were getting lose so I spent ages tweaking each link.
Maybe I'm to heavy footed!

"On one of the chains I'd noticed the links were getting lose so I spent ages tweaking each link."

what is tweaking exactly ?

and yes crossing chains from 38-36 isnt clever

For the OP, where are they snapping? Round the pins or in the link? I use KMC's cheaper X9-93 normally, because I found the lightweight links bent a bit too easily if they chainsuck, but I don't think it's any stronger around the pins.

Don't really understand how people can find SRAM quicklinks better to use than KMC, they're the same design (isn't one of them a licenced copy of the other?) I've used both, there's no difference other than the colour IME.

jamesoz - Member

I wont put another 9 speed KMC chain on a bike, the quick links can and have fallen apart with vibration

How does that work? The chain links are pulled into place every time you pedal, I can see you could possibly vibrate one loose if you stuck it on a cement mixer but when you're riding I can't see how it could happen unless you never pedal.

trail rat - i tightened each link so that no longer had lateral play in the links. Not overtightened them,just tweaked them so they were not loose.
May not be clever but its not like i spend my whole ride in that ratio.
Anything constructive to add?

Hi Northwind - the link is coming away from the pin every time.
I think i will the cheaper version a try!

Personally I would say it is your tweaks that are directly responsible the breaks the chain is not designed to be tweaked

Sancho - are you saying that you shouldn't add additional links to a KMC chain?

Definitely sounds like user error, sorry. It is fine for a chain to have lateral play and I can't see why you would be tightening links.

Having been on KMC X10 (and X9) SL's for the past 5 years the only one I have broken was following a dodgy chainsucky front mech shift climbing a steep gradient and putting the power down which bent a plate which then eventually failed. KMC chains are far more robust than SRAM or Shimano in my experience and stand up to Winter riding far better and give longer cassette life too. The plates are the only possible weakness but when used properly they last the same as any other.

It is essential for a chain to have lateral play, unless you ride a single speed, and I can't see why you would be tightening links.

I'm not saying that at all. But if you are tweaking the chain to take out lateral play then you are weakening thechain

Better phrasing Legend 😀

How does that work? The chain links are pulled into place every time you pedal, I can see you could possibly vibrate one loose if you stuck it on a cement mixer but when you're riding I can't see how it could happen unless you never pedal.

Happened a few times on rough fast descents, possibly when the chain is slack due to being on the 11 tooth on the back and no clutch mech. I've dropped links in the Alps, Wales and Scotland. The chains themselves are plenty strong but the missing links are just too easy to split.

I always run KMC chains. Great value and long-lasting. Maybe you got a bad batch?

Sancho - are you saying that you shouldn't add additional links to a KMC chain?

You should't add additional links without using a quick link. If you've been adding links by pressing the pin out and back in again (like you can do on bmx chains) then this is almost certainly the cause of your breakages.

Never heard of a missing link coming undone by itself! More that they are bloomin' hard to release when you want to get the chain off! It would have to be a link abused for several years before it got loose enough to come undone by itself