There are 2 ways to design an aero profile: use a pencil on a white board or use NACA profiles. NACA means National Advisory Committee for Aeronautics. It was born in the ‘30s and exploded in the ‘60s for a matemathical approach to the complex world of aerodynamics. The shapes of our tubing were born following the NACA “algorithm”, and then adapted at different uses needed on a bike. We considered aerodynamics, weight, and UCI rules limitations to find the best compromise. The result is the new Cento10AIR shape. The downtube, for example, is a NACA profile 0028, which is then cut following the Kamm Tail Theory: this allows us to keep a high aero performance, save weight, increase torsional stiffness, and stay within UCI rules.