My bicycle is almost certainly a Schwinn Sportabout, NOT a Schwinn Continental. Instead of a fancier version of the Schwinn Varsity, I have a cheaper version. I thought it was either a Varsity or a Continental, and because of the tubular (not flat) fork I had been told it was a Continental. However, there were several things that did not fit the specifications of a Continental. For example, mine had a chrome handlebar, bolt-on wheels and side-pull brakes instead of an alloy handlebar, quick release wheels and center-pull brakes. The derailleurs didn't seem right either. I posted a question in the Schwinn Restoration forum and I was informed by a helpful member there that it is most likely a Sportabout, NOT a Continental after all.
There are resources online to decipher Schwinn date codes. The first two letters of the serial number on the head tube (JM513864) indicate my bicycle's frame was built in September 1976. The four digits on the oval head badge (3016) give a more precise build date of . Schwinn introduced a cheaper version of the Varsity called the Sportabout in late Fall 1976. It had a less expensive rolled steel stem, SunTour shift levers, Japanese derailleurs instead of French, SunTour freewheel instead of Maillard, cheaper tires, only two colors (Canary Yellow and Sunset Orange), and a foreign-made one-piece crank with riveted chain ring assembly. It also had the tubular fork usually reserved for Suburbans or Continentals.
My bicycle has a forged stem and Schwinn Twin-Stik shifters, probably a bonus from the factory. Otherwise it matches the specs of a Sportabout. It was yellow when I got it. It has Japanese derailleurs, a SunTour freewheel, the cheaper crank arm, tubular fork (the source of my original misidentification), a black head badge (another characteristic of Sportabouts), and a small flange front hub.
Except for the tubular fork, overall my bike resembled a Varsity more than a Continental. However, the available colors for the Varsity and the Continental in 1976 and those for the Varsity and the Sierra (apparently a replacement for the Continental that year) in 1977 did NOT include yellow as an option. Case closed.