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I’m trying to install a chain with a snap on master link, but I can’t figure out how. I’ve tried twisting the chain as suggested by other questions to get it into place, but that doesn’t help. How do you do this? What’s the secret?

enter image description here

It’s a Shimano 8S CN-HG40 chain.

marked as duplicate by Criggie, Deleted User, Argenti Apparatus, David Richerby, Rory Alsop Nov 18 at 17:24

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  • Correct me, if I'm wrong, but to me the image looks like the gap in the locking plate (on the right) is too narrow for the pins of the master link (on the left). With these snap-on master links, it must be possible to effortlessly thread either single pin through the gap/holes in the locking plate. The locking happens only through the action of both pins together. – cmaster Nov 14 at 8:13
  • I can thread both pins through. This plate is directional, one side is labeled narrow. – EBikeRider Nov 14 at 8:21
  • "Narrow" refers to 3/32" wide chain, as opposed to 1/8" wide chain. Since your chain is 3/32" you should have no problems with installing this master link. Silly question - you are using this master link to connect two narrow (inside) links of the chain, not the outer plates, aren't you? – Mike Nov 14 at 8:52
  • @Mike "you should have no problems with installing this master link" Regardless of whether or not you feel they should be having problems, they are having problems. Telling somebody that their problem shouldn't exist really isn't helpful. – David Richerby Nov 14 at 10:13
  • @DavidRicherby, thank you for your remark. I don't see that OP have problems installing the master link, they simply lack knowledge/skills/tools and ask for help guidance and help. And since fitting a 3/32" master link onto a 3/32" chain should not pose problems, fitting a 3/32" master link onto a 1/8" chain can be somewhat challenging if at all possible. I nevertheless believe that we are here to discuss on a broad topic of bicycles and not on who is having problems and who doesn't. – Mike Nov 14 at 10:35
up vote 25 down vote accepted

The secret is simple, you need to:

  • place the master link (the part with the pins) with the opening towards you,
  • bend (flex) the chain so the open ends of the pins come closer to each other,
  • put the flat part of the master link,
  • release the bend allowing the pins to snap into the flat part of the master link.

Since one picture saves 1000 words, they say... Installing master link

The bend of the chain is a bit exaggerated, only to show the idea of the action required. One bends the chain using their hands.

And from my own experience - I prefer this type of master link over power link since linking and breaking the chain does not require literally any tools (excepto for one's hands) making it great for road-side repairs. Disengaging power link does require at least pliers (dedicated tool recommended) unless one has enormous strength at their fingertips.

  • This helped! I was twisting the chain instead of flexing it. The diagram is what I needed. – EBikeRider Nov 15 at 3:11
  • @EBikeRider - I'm glad I could help. – Mike Nov 15 at 8:37

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