That is the first series of Race bike that Cannondale put out. They started making racing frames in about 1984, yours is a 1986. Back in the 1980's, everybody would make fun of the tube diameter size. Everybody was riding cromoly steel back then. Alcoa is the company that made the aluminum. Hold on to that bike, it's a stiff as can be and great for sprinting. Call 1-800-BIKE-USA and give the operator the serial number, she will tell you all about your beautiful ride.