As the air hit the front of the motorcycle and rider, the balance was deflected – like a swing-boat in a fairground – proportionally to the test object’s aerodynamic profile. This deflection and wind speed were measured and displayed on an illuminated board called the Scala Convenzionale, similar to a giant tachometer. The rider could see the relative effects of his riding position and could change position accordingly. Aerodynamicists would work to develop and change parts of the bodywork to see how they affected the drag performance.
Forward-facing L-shaped pitot tubes mounted in the wall of the wind tunnel measured the wind speed. Each measures air pressure and corrects for changing barometric and static pressure measured at its static port where there is no airflow pressure effect. The pressures were measured on liquid manometers. Temperature and time were recorded in an adjacent control room by the wind tunnel operator, who would also control the wind speed and ensure its safe operation.
Moto Guzzi engineers first used the wind tunnel at Mandello Del Lario for testing racing motorcycles, and it’s understood that Fergus Anderson was the first rider to use it. With innovations such as the 500cc V8 racer’s dustbin fairings, racing and road motorcycles were developed and honed here.