Originally Posted by
cyccommute
It’s been 25 to 30 years since chains could widely have the pin pushed out and be pushed back in again. 9 speed chain and on have universally used peened pins which should not be handled in that way. In general, quick links should be used and they are widely available for the 6/7/8 chains for older bikes or even modern bikes with 7 speed freewheels. They are also just easier to use.
Lots of people have old chains - I have a bunch of old Suntour 6 speed chains NOS. There is no other option with those chains, so suggesting that connecting those chains the only way they can be connected is somehow dangerous boggles the mind.
Peened pins began with Shimano's 4.8mm spaced 8 speed system, not 9. It didn't come to Campy until 9 because their 8 speed was 7 speed spaced. But the one time pins go back to 1990 Dura Ace.