Originally Posted by
docboss
I have enjoyed reading about the Paramount serial number coding issues. Many members certainly seem to know their stuff. I recently corresponded with Richard Schwinn regarding the number on my 1989 Paramount. A couple of things members know or perhaps find interesting: My serial number is 660GMWG89051. I determined that 660 is the size (it's huge) and W meant Waterford (although some say it means Wisconsin). It was made in July 1989 and was the 51st frame (or fork) made, or bike assembled. What was curious was the letter G, which is fork size. I had never read of a fork larger than "E". Mr. Schwinn told me the "M" indicated OS sized tubing, 31.8mm for that year. Could someone tell me if this is correct? Is there anything members can add to this information? Thanks for your help.
The "fork size" is actually the length of the steerer tube, which of course is dependent on the length of the head tube. My 1987 62cm frame (620E WK 87077) has an "E" length steerer, so I'm guessing a 64cm frame would take an "F", and a 66cm frame would take a "G".
I believe Richard is correct about the "M". 1989 was the year the OS Paramounts were introduced, and they were built using True Temper OS tubing which Schwinn called "Paramount Tubing" as it was joint development effort by Schwinn and True Temper. The Paramounts using standard diameter Columbus tubing (SLX on frame sizes up to 57cm; SL with SP down tubes on larger frame sizes) were also available that year.
From the 1989 catalog:
Tubing diameters:
The Columbus tubing Paramounts used standard diameter tubes; the Paramount tubing Paramounts used OS diameter tubes.
