KMC Missing/Quick/Magic Link wearing out before the rest of the chain?

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alcatraz
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Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Hi WW's

Just found that an occasional skip I feel when riding is caused by the quick link. I put on one of my old KMC original quick links and it's the same problem. I measured the chain length on a section with and section without the link and the difference is 1-2 tenths of a millimeter.

I position the link on the cassette and feel the cranks as I slowly roll the link off the cassette and I can feel a slight jump or twitch.

This is quite annoying and I was just wondering if this has happened to you? That means wearing out like 2-3 quick links for every one chain.

Now the distance being similar between the older and current quick link tells me it might be the ends of the chain that attach to the quick link that are worn.

What do you recommend? Should I hunt down some spare quick links or do I have to bite the bullet and get a new chain? What annoys me most is that the chain is showing very little wear elsewhere. I'm at around 0.1-0.2% elongation at the moment. Wouldn't it be silly to throw such a chain away? It's an X10SL.

Has anyone managed to install a KMC chain with a pin instead of a quick link?

Thanks foe your help. /a

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Orlok
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by Orlok

No, I always used the same quick-link with my KMC XL10EL chain and can drive 8K with it without problems like you mentioned. But I always change the chain at 3K even it's before 0,5% elongation and keep the chain as spare part. If your chain is at 0,1% don't trow it away but put a new quick-link in it and use it normally.
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boysa
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by boysa

I had similar issues. Switched to Wipperman quick-release links. Problem solved.
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DuncanS
Posts: 143
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by DuncanS

Yes, I've had the same thing several times. Switched quicklinks but the problem persists. I figure it must be the rollers that the quicklinks go through that wear down.

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bikerjulio
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by bikerjulio

No issues for me over many years, 10 and 11.

BUT there was a thread around a while ago discussing fake links, in which obvious differences to genuine were noted.
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Bridgeman
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by Bridgeman

When I looked into a skipping issue some years ago, I discovered the KMC link as being the problem. After a simple geometric study, I found that the portion of link shoulder that is elongated inward to accommodate the slot was displacing the pin axis upward and off of the 11 sprocket.

The one solution that I did to prove this effect was to dremmel the shoulder of the sprocket at each of the points of contact. It's a pita but it works.

It can be considered a flaw when using the link with Campy, because the designer of the link didn't take this point of contact into account.

I also tried dremmeling the link itself, at the elongated portion, but was hesitant to remove too much material, as it would weaken the link, but it did help with the performance of the chain.

The displacement at the point of contact is very obvious when you overlay the chain on the sprocket shoulder. The fist indication that this was the culprit was when I saw the contact marks at first examination after a fair number of miles were put on the two.
Last edited by Bridgeman on Wed Sep 20, 2017 6:21 am, edited 2 times in total.

alcatraz
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Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

My problem is the chain is clearly longer by around 0.2mm at or around the link.

I got some new links on the way but I fear they will not help as it could have something to do with the link pins being too small in diameter and thus somehow digging into the ends of the actual chain making the end holes a bit oval shaped.

Sounds crazy but I don't know how to better describe it.

/a

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jekyll man
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by jekyll man

Why even bother with the quick link?
Join it normally; does away with the "weakest" link, and also the part you are worried about.

You can always save the link for "emergencies" on the road.
Theyre only meant to be connected once or twice; do you frequently remove the chain for cleaning?
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alcatraz
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by alcatraz

jekyll man wrote:Why even bother with the quick link?
Join it normally; does away with the "weakest" link, and also the part you are worried about.

You can always save the link for "emergencies" on the road.
Theyre only meant to be connected once or twice; do you frequently remove the chain for cleaning?


Don't you need a special pin to join the two sides?

I've taken it off maybe 5 times to wax it. I gotta be honest it's probably been used for almost 5000km but the elongation is only at 0.2%. I think it's from the waxing and from the fact that I'm a lightweight guy at 62kg.

/a

alcatraz
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by alcatraz

Update:

So I replaced the chain and the bike is so much more quiet and smooth now.

What I don't understand is how the old chain can have so little stretch (measured several places) and still be so noisy. I do the wax submersion every ~400km as I did with the new chain and it's smooth after each waxing.

But I got a lot more noises from my drivetrain compared to now. Apart from the missing link twitch I got more pops and creaks with the old chain. Put a chain wear gauge in it and you can't get the 0.75mm to go in anywhere. When measuring like 15links with a tape measure I also last got a stretch of under 0.2%. (missing link part is more).

What gives? Almoat no stretch but still noisy, creaky and poppy?

By the way to solve my problem with the missing link connections wearing out prematurely I just close the chain lightly before rewaxing it. That means the link stays in the chain and so no wax is lost in that area when I install the chain. (If you take it out the link might remove some wax when putting it back on the chain. This is my hope anyway.)

/a

MikeD
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by MikeD

alcatraz wrote:Update:

So I replaced the chain and the bike is so much more quiet and smooth now.

What I don't understand is how the old chain can have so little stretch (measured several places) and still be so noisy. I do the wax submersion every ~400km as I did with the new chain and it's smooth after each waxing.

But I got a lot more noises from my drivetrain compared to now. Apart from the missing link twitch I got more pops and creaks with the old chain. Put a chain wear gauge in it and you can't get the 0.75mm to go in anywhere. When measuring like 15links with a tape measure I also last got a stretch of under 0.2%. (missing link part is more).

What gives? Almoat no stretch but still noisy, creaky and poppy?

By the way to solve my problem with the missing link connections wearing out prematurely I just close the chain lightly before rewaxing it. That means the link stays in the chain and so no wax is lost in that area when I install the chain. (If you take it out the link might remove some wax when putting it back on the chain. This is my hope anyway.)

/a


You are not going to get a quiet chain using wax.

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Mr.Gib
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by Mr.Gib

5000 km is a decent life for a chain. I never get that much. Mine start to get noisier after about 3000 km and while they still function, I am fed up with the noise at 4000 and toss 'em.
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blueturtle
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Joined: Fri Dec 14, 2012 11:09 pm

by blueturtle

Thanks to Alcatraz. Searched high and low to locate the problem with my skipping chain and clicking noise.Changed pedals,swopped chain,changed cassette,checked freewheel all to no avail,that is till i stumbled across Alcatraz,s thread.Changed kmc power link,Hey Presto,100% spot on. All is now well, Cheers. PS made the mistake of changing the chain but not the quick link.

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