I went back and double checked my tires. Clement Paris Roubaix linen kevlar. I'm guessing these were a later incarnation of the Paris Roubaix tire?
The 1981 Bikeology catalogue on Bulgier.net shows a 25mm tire, silk casing with chevron pattern. Palo Alto bicycle shop shows 2 versions of the PR vulcanized and nonvulcanized but other than that I see no differences.
Can anyone give me an idea when my particular Paris Roubaix's originate from?
thanks,
Marty Eison
Frisco, Texas