Originally Posted by
HillRider
OK, I'll accept that but the instances of chains breaking at the properly installed joining pin are very rare. So, while theoretically it's the "weak link", in practice it appears to be more than adequately strong.
To the OP: Go ahead and push out the joining pin to install your master link. It won't damage the chain where it counts and you have removed a potential weak spot.
The only reason why a chain will break at the joining pin is if it was installed incorrectly. Think how absurd it is that shimano would manufacture replacement pins that would fail under normal use with proper installation.