I've been running a Diamond back half link chain on my singlespeed for about three months, and it's awful. It's gained just under an inch in this time, and a few links have split clean apart. Is it just a duff one or is this as good as they get?

al

An inch..?

i had a gusset half link chain which also gained about an inch, and i snapped links clean in two aswell.

run a regular (cheap) 9 speed on the ss now, no problems thus far.

An inch over the whole chain, not just the standard 12 inch ruler. I can almost take another link out of it.

I suspect it's the design of the links that is the problem, the plates on normal links are flat so are at their maximum extension already, whereas halflinks are angled so will stretch and deform more readily.

Back to normal chains now.

I had a Shadow Conspiracy one that stretched a load. No broken links though.

Funnily enough I bought a Charge Masher half link chain less than 2 weeks ago that has bust 3 links so far. I made Evans swap it for new today because of this problem.

Could it be chainline related, causing a slight twist which is accelerating the link failure? Either way, I'm going back to BMX chain plus tensioner

I must admit I was very disapointed with the KMC half link chain that I put on my SS, it too stretched a good inch although it is down to a mm or so each ride now. I will try the BMX chains next too or is it better to just revert back to standard 7 speed/8 speed chains. (I am a big heavy bloke amd am running 32×16 at the moment).

ordinary sram PC1 chains does the job and is cheap – also running a proper single speed chain with a cack /out or alignment chainline will speed the wear rates as they are not designed to run out of line

I tried a Yaban 1/2 link chain, potentially for our 2010 singlespeeds – it didn't break on a 39/17 set up but it stretched fast and was generally not very confidence inspiring when hauling a SS over the last bit of a climb.. useful for whjeel positioning but not great overall.

I think half link chains were initially designed for BMXers who do stalls or grinds on their chainwheel, the theory being that a shorter link is more resistant to bending. I have a Gusset one which I haven't noticed stretching, however I've had the wheel out (and therefore retensioned it) on a fairly regular basis and it is noticeably heavier and less smooth than something like an SRAM PC1.