FREQUENTLY ASKED QUESTIONS
Optimo Aluminum
- What is Optimo aluminum and how was it developed?
- What are the specific properties of Optimo?
- Why doesn't Cannondale use 7000 series alloys?
1. What is Optimo aluminum and how was it developed?
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.
2. What are the specific properties of Optimo?
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. A higher ultimate tensile strength means that Cannondale's engineers can use less material, saving weight while still resulting in a frame that passes Cannondale's industry leading test requirements. The higher elongation makes the welded frame structure less susceptible to fatigue cracks since the material can "stretch" more without initiating the microscopic damage that can grow into cracks.
3. Why doesn't Cannondale use 7000 series alloys?
With over 20 years of building aluminum bikes (Cannondale has never even made a steel frame) our experience has shown us that 6061 and Optimo alloys are superior to 7000 aluminum at the welded joint. Despite advances in heat treatment, 7000 series alloy still exhibit a large drop in mechanical properties at the welded tube junction, resulting a frame that is either heavier or does not pass Cannondale's stringent ESAL testing.
