I just removed some of those from a '73 Gitane. They worked for years, and then for some reason I couldn't get the wheel to stay put in the dropouts. I tried switching QR levers, clamping down as much as I could, checking to be sure the axle wasn't too long, removing the springs used to center the QR skewer... finally a friend said, "Try removing the stops and sliding the wheel all the way back in the dropout." Worked like a charm. I have another Gitane waiting repair so we'll see if they work in that bike...