Thunder on Two Wheels: Mario Mazzetti, Alfonso Morini, and MM in Bologna, 1924

Interwar Bologna was a hotbed of mechanical passion. Mario Mazzetti (1895–1964) understood that superior power-to-weight ratios—not sheer engine displacement—decided road races over dusty, unpaved Italian terrain. In 1924, MM debuted a 125cc two-stroke machine, swiftly followed by a revolutionary 175cc single-cylinder overhead-valve (OHV) engine that produced remarkable rpm for its era.

With Alfonso Morini (1898–1969) crouched over the fuel tank, MM notched sensational victories at the Grand Prix of Nations in Monza and the grueling Milan-Taranto long-distance road race. In 1927, Morini broke six world speed records at Monza aboard an MM 125cc, averaging over 122 km/h. MM’s blue-and-silver racing livery became feared on racetracks across Europe, proving that Bolognese artisans could out-engineer established British and German factories.

MM was not merely a racing stable; it was the fertile nursery from which the entire Emilian motorcycle district sprang. In 1937, Alfonso Morini amicably separated from Mazzetti to establish his own celebrated marque, Moto Morini. While MM ceased motorcycle production in 1957 following Mazzetti’s retirement, its DNA lives on in the metallurgical and design standards of the Motor Valley.

Historical MM competition motorcycles are preserved in prestigious institutions like the Museo del Patrimonio Industriale di Bologna and private motor museums in Sant’Agata Bolognese, revering the small workshop on Via Fioravanti where modern Italian motorcycle supremacy first took flight in 1924.