The Rumi organisation was founded at the beginning of the twentieth century, initially supplying cast components to the textile machinery industry. During World War II, the company shifted to armaments production, manufacturing miniature submarines and torpedoes. After the war, Rumi's director Donnino Rumi — later known as a sculptor and artist — decided to apply the company's casting expertise to lightweight motorcycles, entering production around 1950.
The basis of Rumi's motorcycle design was a horizontal twin-cylinder two-stroke engine of 125 cc displacement, a configuration that gave the machines a low centre of gravity and distinctive character compared to conventional vertical-cylinder rivals.
Rumi entered Grand Prix motorcycle racing in the 125 cc class during the early 1950s with factory-prepared versions of their road-derived hardware. By 1952, the company was producing the "Competizione" — also known as the "Gobbetto" — a dedicated factory racer developed from the twin-carburettor "super sport" road model.
The Competizione achieved significant domestic success: it won the Italian National Championship in 1954, demonstrating the competitiveness of the horizontal twin layout against more conventional designs. The "Junior Corsa" and "Junior Gentleman" models followed in 1955, continuing Rumi's programme of racing development.
In 1957, 1958, and 1960, Rumi achieved international recognition by winning the famous Bol d'Or 24-hour endurance race held at Montlhery in France. These victories over distance underlined the reliability of the two-stroke twin configuration and established Rumi as a credible force beyond domestic Italian competition.
In parallel with racing, Rumi developed a range of road machines exploiting their aluminium casting capability. The Squirrel (Scoiattolo) scooter, introduced in 1952, featured a cast aluminium monocoque body with tubular swinging arm rear suspension, telefork front suspension, 14-inch wheels, and three gears, with later versions gaining a four-speed gearbox and electric starter. Contemporary accounts described the Squirrel as among the fastest scooters in production.
The Formichino (Little Ant) scooter followed in 1954, reputedly designed by an engineer named Salvatti. Like the Squirrel, it used a cast aluminium body — front and rear castings bolted directly to the engine to form a monocoque structure — giving a light and rigid result. The Formichino's wheels grew from 8 inches to 10 inches by 1958 for improved stability and ground clearance.
A Bol d'Or scooter model was produced to commemorate the endurance race victories, featuring dropped handlebars, chrome-plated aluminium cylinders, and twin carburettors in the UK-market version, while the French version used a single 22 mm carburettor.
During the 1960s, Moto Rumi went into liquidation as the Italian motorcycle industry consolidated and cheaper mass-produced machines outcompeted specialist constructors. Donnino Rumi subsequently returned to his career as a sculptor and artist. The company's legacy rests on the originality of its engineering approach and its victories in domestic and endurance competition during Italian motorcycling's most creative decade.