smd4

I was thumbing through Eugene Sloane's "All New Complete Book of Cycling," c. 1980, and in the chapter on chains, there's a photo of a Shimano quick link that looks remarkably similar to the ones we use today--with a wide hole closer to the center of the link, narrowing as it goes toward the end of the link.

I never would have though the quick link concept went back at least 42 years. Sure, BMX bikes and a few others had "master links," but the no-tool-necessary quick-link concept apparently goes back much farther than I would have thought. Except for the one in the photo, I have never seen a similar link in any shop I worked at.