How does a Half-Link work?

As the title suggests, I’m having trouble getting my head around how a half link actually works?
I mean, the pitch of the chain is always 1/2 inch right…
Confused :? :?

Can someone explain it in terms of

“a half-link is used to ------------------------ for the chain.”

Come on all you Sheldon wanabes! :mrgreen:

if you think of the chain as being made of two alternating pieces, call them odd and even, when you remove one ‘even’ link, you can’t join an odd to an odd, so you have to always remove two links, an odd and an even. the half link enables you to join an odd to an odd, therefore enabling you to remove one link, and still rejoin your chain.

is that make sense???

Thankyou. Crystal clear.

A half link is used to obtain an odd number of teeth in your chain. Normally you can only get an even number since each chain link has two teeth (an outer plate and an inner).

To use the kind pictured:

  • break your chain keeping an outer plate with a pin in the section you wish to keep.
  • push the pin through the bendy section side of the half-link, joining the half-link into the main chain
  • join the chain as before - now with an odd number of teeth.

If anyone would like a demo - let me know and i’ll paste some photos - or just ask Sheldon.

(Damn Liam beat me to it ;)[edit: terminology]

Have a look at your chain Horatio.

A full link is made up of a set of “outer” plates and “inner” plates and is equal to two teeth on a ring/cog.

A half-link is shaped such that one end will be “inner” and the other end will be “outer”. You can clearly see this in the pic shortsie posted (The bit on the left is the half-link. The bit on the right is the inner link from a normal chain). The half-link allows you to adjust your chain length by one “tooth” compared to “two teeth” at a time if using normal links. This means you have more options when finding a “magic gear” for vertical dropout conversions. I’ve used a half-link to some success on my last conversion.


Chain, chain… is that the thing that… :evil:

Thankyou all for your clear desciption. I completely understand how it works now, cheers. I’m asking on behalf of my work colleague who is indeed in search of ‘the magic gear’ (no dropout adjustment and doesn’t like his chain tensioner).

So Des, did you use a half-link because you didn’t have dropout adjustment? And do they work well?
Aerospoke Aerospoke Aerospoke gee, the censor really DOES work. Amazing technology!

what word does the censor work for?

aerospoke … duh :wink:

Yes. I used it on a frame with vertical dropouts. They work. The problem is that you might still have to fiddle with “different” chains to get magic gear to work. By different I mean, stretched vs. non-stretched chains. To give you an example … on my cross bike, if I’m using 44x18, I’ll need a normal chain that is used and therefore pre-stretched. A new chain will be too tight and will not fit. I’m now using 39x17 and need a new chain with a half-link. The chain is getting loose now and I’ve dropped it on one occasion when I hit a bump on the road. Note that I’m also using a chainring and cog that are meant for multi-geared bikes so and if I had used SS specific stuff with non-ramped and taller teeth, that would not have happened.

Bottom-line … they work … but you can’t do micro-adjustments to compensate for chain-stretch or may have to pre-stretch to fit.


wiseguy :slight_smile:

Would anyone like to endorse or shoot down the ‘entire chain made of half-links’ that looks equal parts ‘a bit heavy’, ‘awesome’ and ‘a bit like a caterpillar tread’…

the kind that looks a bit like this …

/- /- /- /- /- /- -
-/ --/ --/ --/ --/ --/ --/
-\ --\ --\ --\ --\ --\ --\
- - - - - - -

instead of the ‘normal’


I would like to endorse your ASCI chain :slight_smile:

the connex 1g8 chain looks heavy and awesome, but not made from halflinks. theoretically it would be lighter and stiffer then a halflink chain

they do indeed look awesome. I gather they’re a bit more prone to stretching than regular chains since the plates are bent in/pinched/kinked so there is scope for the plates to be less kinked (ie straighter), thus more “stretched”

A mate of mine used to have one on his singlespeed mtb. It looked wicked. Not sure about weight and stretch though.

Was it Theo?

It stretches quite a bit. I had a half link chain on my last bike because the front-facing, semi-horizontal dropouts were too short for the gear I was using with a normal chain (it would be either too slack or too taught). The chain stretched within 2-3 months of riding a short to moderate distance everyday and it chewed up my cheap aluminium chainring. Bastard. So I bought a new bike :slight_smile: