The first road frame from Cannondale was produced in 1983. It sold for $350 and included the frame and fork. The fork was steel with helical reinforcement ribs inside the steel steering tube. The frame was instantly recognized for the oversized down tube and enlarged head tube. The seat-stays and chain-stays were ovalized to reduce flex. Unlike steel frames, there were no lugs; the aluminum tubes were mitered, hand welded and then heat treated.
The first frames were available in two colors; red and white, and painted with DuPont Imron paint. Cannondale achieved the distinction and goal of becoming the first high volume producer of aluminum frames, at a time when only steel frames were mass produced and aluminum was hand made in low volumes.
Cannondale marketed subsequent frames with the CAAD designation (for "Cannondale Advanced Aluminum Design"). The CAAD4 model introduced S-bend aluminum seat stays for improved comfort. Optimo aluminum was developed in a partnership with Alcoa and was introduced to the market in 2002 with the CAAD7 road frame. The development process of the specific elements of the alloy took over 18 months, and Cannondale has exclusive use of this alloy in the bicycle industry.
Optimo aluminum is a 6000 series alloy that has superior properties to 6061, 6066, and 6069. Compared to 6061, Optimo's proprietary mix contains slightly more silicon and less magnesium, which results in higher ultimate tensile strength and higher elongation.
The current generation of Cannondale aluminum frame in the 2007 model year is known as CAAD9. CAAD9 is the continued evolution of Cannondale's welded aluminum frame design. CAAD 9 has reduced weight and increased stiffness over last year's CAAD8 design.
(from http://en.wikipedia.org/wiki/Cannondale ... orporation