Originally Posted by
MudPie
Once you break a Shimano chain, do not reuse the old pin - you need to use a new pin (available at your LBS). The new pin is inserted with a chain tool and not peened like the factory pins.
Actually, the replacement pin is peened, but since driving out the original pin enlarges the hole in the link, the replacement pin is slightly larger in diameter. You can feel it snap into place when installing it.
I agree with the others- the SRAM master links are much, much nicer than the Shimano replacement pin. In fact, I've converted to using SRAM chains exclusively on my bikes.