I am not sure these are period correct, but they were introduced in the 1980s. I had good luck with these...when one wore out, I removed the polyurethane belt and used it in a clincher...pre Mr. Tuffy. I know the belts didn't help the ride/feel of the tires, but I was a poor student racer and never got past Cat III anyway. Silks were for the guys that drove BMWs (Mike Kone, are you listening?) Does anyone have a recommendation for a current belted/armored tubular? Ed Kasper Detroit MI (20+ mph wind and snow squalls on yesterday's ride...42x19 out, 52x14 back...just goes to show: Its not where you are, but which way you are going).