Bike Chain master links.

[stts]

I don't see anything about these and they ended up being tricky. Chains have all kinds of widths. If you measure the pin width, its bigger than the link width because the pin has to stick out to be crimped or swaged. But if you notice the master links, the pin is swaged flush with the link plates. So pin width of chain is NOT pin width of the master link. But master link pin width IS the same width as the chain link width. So get links with Pin width the same as chain link width and you should be fine. Now for the next screwy detail. Some links are sold as 5 to 10 speed links. And they come stamped 6S. And then you find they don't fit your 5 to 10 speed chain. That can be a bummer. My sprocket is 6 speeds and the 6S link is too skinny for my chain. So you cant trust the number stamp on the link. There's another identifier used on the MissingLink brand that starts with CL. There's lots of these CL numbers like cl552, cl555, cl559, cl566, cl571, cl573, etc. And they are very good numbers to see. Because for cl552, the link pin width is 5.2mm. My 6S link I got from amazon had no cl number. But measured out as 6.6mm. But my chain from KMC measures at 7.1mm link width. The KMC pins stick out for mashing so the chain pin width is even longer. So I had to order more master links with a stamp on the link that says CL571. There is considerable slop in the chain between the skinny link and the fat link to leave room for dirt. So slight master link disrepencies should not be a problem. But the difference between 6.6mm and 7.1mm is just not workable. The master pin doesn't stick out to close the master link. . So ignore all the 6s,7s,8s,9s,10s type markings and always go with links with a CL stamp on them. Then you know exactly what bike chain your link should fit. Good pictures will show, and the CL number in the details is even better. Of course none of this info is any good for Acme chain. For that, look up tips from Wile E Coyote. :)

So to make it a bit clearer, if you can figure out your make and model of your chain, you can hunt for the matching master link from the chain maker for your model of chain. Then pay the bill they send you. Hah. But lots of generic makers are making the same type of bike chains for drastically reduced pricing. But generic chains and parts are not very clear in their advertising. But I figured out that the CL number directly spells out the critical bike chain dimension. In the first pic of these KMC chinese knock offs, you can see that they are stamped CL571R. That means you know they are the 7.1mm pin dimension. And you can see that the pin is flush with the plate. So in the second pic, you can measure your chain at the point of the red arrows. If it's 7.1mm, then these master links will fit the chain. CL573R may fit the chain too, but those links might be too wide for your particular cassette. The "R" means the link is reopenable. Some links have tiny tabs that lock and cant be reopened. So...

CL552 = 5.2mm Link Pin Length
CL555 = 5.5mm Link Pin Length
CL559 = 5.9mm Link Pin Length
CL566 = 6.6mm Link Pin Length
CL571 = 7.1mm Link Pin Length
CL573 = 7.3mm Link Pin Length

So measure your chain at the RED arrows and pick the link that closest fits your measurement and you sure to get a master link that fits your bike. I would avoid any link that is not plainly marked with the CL number unless you can measure the link yourself.

These 5 links I bought for $4.1 on Amazon. Now they are up to $5.37. A bargain compared to the KMC pricing.

[73Eldo]

That was a little hard to follow and read. What brand of chains are you dealing with?

The last 10 or so years I have dealt with Shimano, Sram, and KMC chains. If they didn't come with a pin or link I have bought KMC quick links and have not had any issues just going by the 'speeds'.

I think things get more wacky for 11 and 12 speed but 6-10 I have not had issues. I also have not tried any link brands other than KMC so maybe different brands are more wacky?

[Retrorockit]

Tests have shown the Wippermann Connex to be stronger than others (and like all things WM more expensive). I broke about 3 of them in my somewhat frantic SoFla urban riding. So I started riveting my WM 8SE Ebike chains. I haven't brokan a Connex since then. Of cours ethe Rohloff Revolver rivet peening tool was even more pricey. Since each chain comes with one I have a few of them now.
I think this has solved the problem. I discuss this in the latest post.

https://electricbike.com/forum/forum/main-forum/diy-discussion/156222-mid-drive-cassettte-zip-tie-mod

I may try a Connex again next time, but it is a weak link in the chain, and I'm now doing full power launches in my 2 crosschained lowest gears. I already bought the tool. So maybe that's not going to happen on this bike.. I've custom stacked a cassette that will have me launching from traffic lights in one of those gears.

[stts]

No doubt there are stronger alternatives, but having several cheap little links that fit are excellent items to keep in your bike bag of tools. I doubt I can peddle break these cheap links, but I may have to get better ones when I go electric. Hard to say right now as I plan to make a shock mount for my motor. I don't anticipate any where near the shock loads that everybody else has to put up with. So its possible I can do well with these cheap links. Time will tell.

[AZguy]

Like 73Eldo I just buy KMC 11sp links and call it a day without any drama... they are reasonably priced and never had any issues or concerns with them... even though they say one time use I reuse them and only replace when I replace the chain - last chain >3000mi

When riding I keep a spare with a chain tool just in case... one time years ago that got me home after my one and only chain break in the 50+yrs I've been riding (this was when I first got into the high gear chains and didn't realize the pins couldn't be reused, so not really a failure of the chain, more a failure of the mechanic... yeah me) so not really a big concern but my trusty tiny little park tool chain breaker is so small, so why not?

YMMV

[designerron]

Also check the Pitch dimension of your connecting link. I found that the SRAM quick links were slightly longer than the actual chain links, but KMC links were a better match, a good fit and reusable.

[stts]

Yea I looked up Connex and they post all of their chain dimensions, So you can pick and choose the fit you need from what they offer. And they do have very nice construction in their chains that you pay more for. They have a PDF to download with a handy chart of chain dimensions. KMC chain like I have comes in at half the cost of Connex, But their links are still pricey. My KMC links arriving tuesday are so much cheaper that they have to be knock offs But they are steel, so they should be fine for average needs. The rollers are on the chain so the link is strictly tensile loading. And with the CL labeling, they should fit perfect on my KMC chain. The first batch of links that I got would have been fine if they had actually fit. I already returned them for a refund. Amazon is great for that.

[designerron]

I haven't measured my chain when new and just assume it is zero stretch. I change when it's 0.5 with the simple Park Tool device. I have tried KMC, but they don't last as long. If KMC is already stretched when new, that would explain why I get double the mileage with SRAM ...and a KMC link.

[Retrorockit]

I think SRAM and KMC link sounds pretty good from what I've seen. I was already running Wippermann when I added my BBSHD. So changing didn't seem to make much sense.

[Retrorockit]

https://cyclingtips.com/2019/01/chain-quick-links-guide-to-easy-connection/

[Retrorockit]

It turns out my Connex is know to have side play, and not wear as well as others, but is actually tool less, and supposedly re-useable by pedalists.
Supposedly they're stronger. But like many thing "not strong enough" for my use.

[stts]

eBikes will be stressing all chains way more than they have ever been. So really good lube will help in giving them the best performance possible. I got me a tube of Muc Off because it has additives that really fight against wear. I saw a video of this compared to half a dozen other lubes on a digital wear machine that showed how tough Muc Off was to fighting wear. I got the Wet version because it doesn't dry out like the dry version. So my chain will always have good lube even if I forget to oil it. The dry version is also tough but water works to wash it off and it also slowly flakes off when dry. Good to slough off dirt, but more chain wear in time without regular reapplication.

[designerron]

Good article! My new 12 speed bike has all Shimano, and I have to agree that the Shimano quick link requires more force to lock the link than KMC or SRAM. I'm sticking with Shimano on that bike for now because the price and durability meet my needs.