Broken quick link

RayKinsella

Just came off my bike due to a broken quick-link (again).

There had been a creak down there for the last 2-3 rides. I should have known better not to ignore it. Second short climb of the ride, and snap. I got away with a few cuts and bruises only.

This happened to me also about two years ago. I can't remember who fitted this particular quick link, me or the bike shop, probably me - but they seem to be hard to get right.

The bike shop says - drop the bike in, we will repair NP, but I am suspicious.
Is there a specific chain or brand of quick link that is less prone to others?

Bike's mech is Tiagra.

Ray K

pblakeney

More relevant is the model of chain and quick link.

laurentian

. . . and making sure you have the correct link for the chain size (e.g. 8sp, 9sp, 10 sp)

RayKinsella

pblakeney said:

More relevant is the model of chain and quick link.

No idea on either, what brand do you recommend?

MattFalle

Get yourself a new KMC chain and link to match whatever speed set up you have. Sorted.

pblakeney

RayKinsella said:

pblakeney said:

More relevant is the model of chain and quick link.

No idea on either, what brand do you recommend?

What MatteFalle says above.
That said, no recognised brand quick link should fail if fitted properly.

RayKinsella

Both were definitely recognized brands - can't help feeling I screwed up fitting it somehow.

joeyhalloran

Did you refit the same one? For example during cleaning? I'd have thought you'd realise if it was improperly fitted as the gears wouldn't be smooth due to the slightly shorter link it would create.

imposter2.0

RayKinsella said:

but they seem to be hard to get right.

Quick links are incredibly simple and (notwithstanding this example) very reliable. Would be interesting to know how the link failed.

RayKinsella

didn't get a good look at it yet.

sungod

i've not had a quick link fail in >12 years

if you've had two fail just two years apart, something is wrong, it's hard to see how incorrect fitting wouldn't have been obvious far sooner

what speed chain? was the quick link the correct one for that speed?

had the link been removed and refitted?

if it was not the re-usable type, bear in mind they can be damaged by re-use

exactly how did it fail? plate broke? pin detached? pin snapped?

how worn was the chain? if pin-pin distance for the pins closest to 12 inches apart is <= 12 1/6 inches that's ok, if it's > 12 1/8 inches, then that's pretty worn

RayKinsella

Plate broke and pin detached.

RayKinsella

So this bike was in the bike shop in August but I can't remember if the cassette and chain were replaced then.

pblakeney

If you didn't fit it yourself I would find a new bike shop.

grenw

Just buy a KMC chain. They all come with the required quick link. Been using them on road and mountain bikes for a decade or so and never had a problem

redvision

OP, was it definitely a quick link or was it one of the shimano chain connector pins?

I switched away from shimano chains when I had two snap in short succession - both times out was the connecting pin.

Never had a quick link snap.

Munsford0

I've had a 10 speed KMC quick link fail. Fortunately it was sitting in a jar of white spirit at the time with the rest of the chain during cleaning. Pin just fell out of the side plate.

Could have been self-inflicted by reusing the thing too often though...

webboo

I’ve had a quick link fail, the end of the plate snapped off. I can’t remember what make it was, it had been creaking a bit before it went. I just thought it was something else making the noise.
I also had one undo it’s self when changing gear but that was when they first came out.

me-109

I've just had a KMC X11 fail twice, almost identical failures. Both times at normal outer plates, replacing the first failed outer plate with another quick link. Second failure about a dozen links round from the first failure point. No creaking or advance warning. Not even worn to first option on the checker (0.5%?).

daniel_b

Do those with breaking quicklinks put out a lot of power, sprint a bit maybe?

I'm distinctly average in terms of power output, am not a sprinter by any means, and have never had one break, in around 15 years of riding.

That's a mix of shimano and kmc chains, 9, 10, 11 and 12 speed chains.

Munsford0

daniel_b said:

Do those with breaking quicklinks put out a lot of power, sprint a bit maybe?

In my case, absoultely not.

dabber

I had a KMC (11) quicklink break as I'd just crested the top of a climb in France. The last 100 metres or so of the climb was around 12% and I'd been out of the saddle.
I was lucky in that having crested it I'd sat down again. It could have been painful if I'd been out of the saddle.
One of the quicklink pins had sort of pulled away from the link.

webboo

Mine broke during an interval session on the road. Doing 20 second on 40 seconds off, out of the saddle sprint to start. I’ve no idea what level of power was being generated but I presume it was fairly low.

sungod

fwiw i use the wippermann connex links

these are easy fingers-only to fit/remove/re-fit for chain cleaning, pretty much impossible to damage in the process

btw at times there're suggestions of chains cracking due to the effects of water or cleaning/degreasing products after long-term exposure

not sure there's any definitive info on this, but from this old article from leonard zinn, who's generally well regarded, there may be instances where it can happen...

https://www.velonews.com/gear/technical-qa-with-lennard-zinn-not-so-simple-green-2/

pinno

sungod said:

fwiw i use the wippermann connex links

Only 'cos I recommended them

I've used this type of link ever since a KMC link broke on me.
No issues in 4+ years of using the Wipperman connex.

wobblebob

My wipperman connex link broke, the pin/roller came out of one side as I was out of the saddle climbing.

imposter2.0

daniel_b said:

Do those with breaking quicklinks put out a lot of power, sprint a bit maybe?

The links are designed to withstand the same amount of force as the rest of the chain - so in that sense, it wouldn't make any difference - especially at amateur level.

And on the topic of Wippermann quick links - the only quick link failure I've ever experienced was with a Wippermann chain.

webboo

Any one who watch’s cyclocross will be aware that a broken chain is not an unusual occurrence at the start. Given you have to get your foot in quickly then pedal fast and going down the sprockets with some urgency. I would suspect that it’s the rapid sideways force that causes these failures.
Whether this is true I’ve no real idea but no doubt someone will put me right shortly.

daniel_b

imposter2.0 said:

daniel_b said:

Do those with breaking quicklinks put out a lot of power, sprint a bit maybe?

The links are designed to withstand the same amount of force as the rest of the chain - so in that sense, it wouldn't make any difference - especially at amateur level.

And on the topic of Wippermann quick links - the only quick link failure I've ever experienced was with a Wippermann chain.

There seems to be something that on occasion makes them (sorry) the weakest link in the chain though.

Otherwise there would be as many people mentioning their chain had broken on a standard link.

Unless Webboo makes a viable suggestion.

sungod

one way the wippermann links may be more vulnerable than links that need a lot of force to fit/remove, is when freewheeling with a sticky freehub

if the link is on top and at/near the chainring, a sticky freehub can 'pile up' the chain against it

combine that with a bit of jiggling and/or cross chaining, it might be possible for one side of the link to open

if it's the link with the leading pin, it'd still pass through the rear mech etc. without snagging, then it'd be just a matter of time until the asymmetric load causes pin-plate failure

pure conjecture, but given there's almost no force needed to remove a link from an un-tensioned chain, it doesn't seem impossible

but without hard data on failures vs. population, usage, conditions, maintenance, etc., there's no way of knowing whether links are any more/less likely to fail than traditional pin-joined chains

fwiw i've only had two chains break, both old-style pins - not fitted by me, the bikes were provided at a place we were renting, presumably failed due to cack-handed assembly, one lasted less than ten metres

basing things on forum postings etc. isn't reliable - look at the posts here on issues with tubeless tyres, disk brakes, hydraulic brakes etc., seem to outnumber equivalent issues with presumably more numerous older tech, but i'd assume people don't post about those so much anymore

bb chain break mentions, plenty with no quick link involved...

https://forum.bikeradar.com/search?Search=broken+chain

stuff breaks

imposter2.0

daniel_b said:

imposter2.0 said:

daniel_b said:

Do those with breaking quicklinks put out a lot of power, sprint a bit maybe?

The links are designed to withstand the same amount of force as the rest of the chain - so in that sense, it wouldn't make any difference - especially at amateur level.

And on the topic of Wippermann quick links - the only quick link failure I've ever experienced was with a Wippermann chain.

There seems to be something that on occasion makes them (sorry) the weakest link in the chain though.

Otherwise there would be as many people mentioning their chain had broken on a standard link.

Unless Webboo makes a viable suggestion.

Lateral forces are probably a major cause, as mentioned. Track chains are also invariably joined by some form of joining link, but it's rare to see them fail - perhaps because of a lack of lateral forces. The forces going through the chain at the start of a kilo, or team sprint, etc are probably far higher than a road sprinter would ever manage - mainly because the highest force is applied at zero velocity.