I'm having a little trouble following you here, did the side plates
break or did the pins slip out of the side plate? One of those things
seems quite believable and the other completely not. I would even
entertain that the plastic replacement pins that Shimano provides to
put a chain back together with could break...(never seen it happen but
I didn't like the idea and refused to use them for any length of time
myself) Why would one put plastic bits in their drive chain...crack,
either smoking it or having one's head up it? Then again, the pin is
pretty much just to hold the inner and outer side plates together and
the real stress should be on the flanges of the side plates
themselves, not the pin... but I don't trust plastic pins on my chain.
I wouldn't use these:
http://www.rei.com/product/544076
I maintain that the gear ratio used when starting from a stop has no
bearing on the life of the chain, maintenance on the other hand does.
I further assert that side plates don't stretch either and that the
actual cause of what people tend to call 'chain stretch' is actually
the side plates wearing into the pins. I'd like to take credit for
that idea, but I'm pretty certain I heard it from Sheldon Brown
first. I have personally confirmed it by careful disassembly,
inspection, and measurement of a 'stretched' chain. There is
certainly some evidence to support the idea that repeatedly rubbing
two pieces of metal against each other will cause a loss of mass in
one or both pieces and this seems to be what has happened rather than
the side plates becoming elongated.
Would flipping your chain around say every 20k miles extend its life?
You would be wearing down the other side of the pin and wallowing out
the other side of the side plate hole. Rotating your chain will have
more of a bearing on its usable life span than not shifting to low
before stopping will.
> I had two SRAM PC-48 chains break at the side plates.
>
> I think its just cheap manufacturing for that model of
> chain. I now use PC-68s.
>
> Probably most likely chain failure is because the pin
> wasn't properly installed. Chains for the most part
> don't break, no matter how much torque you are able to
> apply to it.
>
> I stay away from "pinned" chains now too. The master
> link is much superior IMHO.
>
> SMH