Originally Posted by
chaadster
Good point regarding chain tech; they're so much better these days. I still seem to remember a time when derailleur tech would not, and I mean literally would not, successfully execute most shifts under load. It was a long time back so I can't recall which or when specifically, so maybe my memory misleads me!
The difference between before and after is the cut down teeth, or shift gates, which make shifting so much easier. The trade off is that that easier shifting comes at the cost of added twisting and side stress on the chains. That was addressed with the peened plates, which is why it's no longer reliable to push back rivets when cutting and splicing chains.
It's one of those "swallowed a fly....." deals, where solving one problem causes another, which is then solved, causing yet another and so on....