Originally Posted by maddog34

look at the pin ends... they are PEENED(slightly flared by force) at the factory... this is why the pin is difficult to move at first when removing them... once pressed out by the breaker tool, that peen becomes smaller... when reinstalled, the pin is no longer securely held in place... some pins can be slightly re-peened to aid their staying put... some can not.... the margin of material is severely reduced in the narrower chains used by 9, 10, and 11 speed gear bikes... the pin may walk back out if it's not peened, and they usually do so under heavy load while climbing...

no peening done? prepare to sing soprano in church tomorrow. :-o