My friend's bike needs a new chain. Looking at the chain, it looks like the pins have a slot for a flat head screwdriver? Is this just cosmetic or does this type of chain require unscrewing the pins? If so could it be replaced with a regular modern chain (of appropriate type [10-speed road])? My question is referring specifically to the pins of this chain which are visible in the attached photos. You can't see it in the picture, but the chain is HKK brand and it was on the bike when he bought it (used)



  • those are just to remove weight. Commented Jan 3, 2018 at 2:41

3 Answers 3


Different chains, including modern ones, have all sorts of patterns or markings on the tips of the pins. On some there's some level of intentionality to it as a shift aid. There are no bike chains where all the links are screwed together. (There are some half-link styles where the pin screws in place, but that's a tangent.)

The pictured chain is an older bushing-type chain, which was the norm until bushingless chains took their place.

From the look of the cranks/rings/guard the bike is a bike-boom era 10 or 12 speed (as in 2 front chainrings and either 5 or 6 rear cogs). If so, chains specific to such drivetrains, which are labelled 5/6 speed usually, are still made and available. You could order one, but many shops don't carry them, instead choosing to use more modern 8-speed chain for replacements on such bikes, which works perfectly.

  • 1
    Clarifying point for OP: the number of speeds a chain is for corresponds to the number of sprockets at the rear wheel only, not the total number of gears the bike has, hence you need a chain for 8 or less sprockets. (At 9 speeds and more, chains get narrower.) Commented Dec 29, 2017 at 13:18
  • Maybe incorporate the above comment into the answer and also clarify that by "10 or 12 speed" you mean in total.
    – Nobody
    Commented Dec 29, 2017 at 14:57
  • @Nobody Is it OK to add comments to someone else's answer? I thought that was frowned upon.
    – Mr Lister
    Commented Dec 29, 2017 at 17:57
  • @MrLister Well if they are really comments then I wouldn't, but this is a straight-forward minor improvement. I think it even would have been ok to just edit it in (owner can reverse it if they want), the way it is now Nathan would need to to phrase it himself if he wanted to add it. So I think an edit would have been even more helpful. Or maybe someone more experienced on SE will correct me.
    – Nobody
    Commented Dec 29, 2017 at 18:01

The horizontal marks on the rivets that you think are screw heads are just an artifact of the older riveting process. You'd take them out using a standard chain breaker.

Newer chains tend to use a different process to join chains together so that mark isn't visible anymore.


No. Its just drastically badly worn and needs to be replaced to avoid skipping and mis-shifts.

Measure off 12 links (12 inner and 12 outer) and it should be exactly 12 inches long. if its 12 and 1/8" long for 12 links its totally dead and you need to replace the cassette.

Often the chainring is savable, because it has more teeth to spread the load. Yours look okay.

  • 1
    I agree that it is drastically worn and needs to be replaced- measuring for chain stretch here would be moot- but are you saying that the flat head looking pattern in the pins are from chain wear? Not sure if this is clear, but this pattern is on every pin.
    – user74671
    Commented Dec 29, 2017 at 5:06
  • @user74671 nope - I suspect the chain might be original, or otherwise many years old. It doesn't appear to be a slot for a screwdriver - its more of how the pins were driven years ago on thicker 5 speed chains like this.
    – Criggie
    Commented Dec 29, 2017 at 9:59

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