As I've stated in so many other posts, I'm new to all this stuff. I think I have made the realization that there is no real rhyme or reason as to when Skip Tooth chan use saw it's end. Is it safe to say that manufacturers built bikes with EITHER type of chain configuration over a period of years? That is, "So-And-So Bike Co." did/did not stop using skip tooth hardware on this particular date? I'm beginning to assume that drive-train parts were used up until inventory was gone, all the while 1/2 inch stuff was being put out there at the same time, by the same builder, in the same production year. Is that a safe statement?