Cyclologist

As the title states, the master pin (the one pin Shimano says not to touch) in a Shimano Ultegra 10 spd chain is protruding to one side, so much so the other side is flush, if not slightly recessed. This can't be good. Should I give it a nudge with a chain tool or is this chain toast? My other option is to get rid of the offending link and replace with backup links I have laying around along with the appropriate replacement pins.

nitropowered

just take the chain tool and push the chain back in. The second shelf on the park chain tool works well for this.

HillRider

It sounds like it wasn't installed properly to begin with so use your chain tool to seat it completely. Done right, it should not create a stiff link. Shimano says not to push it out to "break" the chain for cleaning but it should be installed correctly at first.

Cyclologist

Well, I pushed it in in the right direction and it isn't stiff. I'll have to keep an eye on it to make sure it isn't wiggling out again.

I remember taking note of this pin when I first got the chain, and I distinctly remember it being fine. There were a few unexplained drive-train mishaps which might have caused the pin to wiggle in one direction. My only concern now is whether the side that became flush, if not recessed, still has a fat head to keep it from going through all the way and that the pin has not become 'accustomed to' and 'prefer' the wrong position.

Nessism

I'd adjust the pin to center, and make sure you don't create a stiff link. Assuming all goes well, watch the pin to make sure it doesn't move again. If it does, get a master link of some kind and ditch the pin all together.