Rather than just employing circular cross section tubes of varying diameters and thickness like the Cannondales, the Columbus aluminum alloy tubesets use non-circular triangular/ovalized cross sections that are geometrically varied longitudinally. This more advanced design approach is an excellent way of controlling responses to assorted directional loads while avoiding the large diameters and thin walls that are more susceptible to denting...rightly said "......it's all about engineering".