Comparing the Moto Guzzi Stornello with its single-cylinder rivals, the Ducati 125 Sport and Motobi 125 Sport Special.
Moto Guzzi Stornello
Years produced: 1961-1974
Power: 8.5hp @ 7,500rpm (1965 Sport)
Top speed: 70mph (claimed)
Engine: 123cc (52mm x 58mm) air-cooled OHV single
Transmission: 4-speed, chain final drive
Weight/MPG: 202lb (dry)/100mpg (claimed)
Price then/now: NA/$1,500-$4,000
Just as the Mini did in Britain, Fiat’s 500 Cinquecento, introduced in 1957, devastated the Italian motorcycle industry in the 1960s. With more than 500,000 motorcycles produced in 1959, the industry was coming off a record year and the future looked bright. Yet by the end of the next decade, famous names like Bianchi, FB Mondial, Rumi, Ceccato and Itom had either ceased motorcycle production or were absorbed into larger companies like Piaggio. Those that survived the decade (Moto Guzzi, Ducati and Benelli, for example) did so by producing sturdy and sporty small bikes for those still unable or unwilling to buy a car. This led to the increasing importance of the 125cc class: Guzzi’s Stornello (“Starling”) of 1961 perfectly fit the new market reality.
Better known for his race bikes, it was Guzzi’s Giulio Carcano who designed the modest Stornello. Yet while keeping production costs in check, Carcano nevertheless penned a proper motorcycle with a dual-downtube, open-cradle steel frame, dual shocks controlling the swingarm rear suspension and a hydraulically damped telescopic front fork. The chassis ran on 17-inch steel-rim wheels shod with 2.75-inch rear and 2.5-inch front tires. Brakes were single-leading-shoe front and rear, and approximately 5-1/4 inches in diameter.
The iron-cylindered 123cc (52mm x 58mm bore and stroke) 4-stroke single featured two parallel overhead valves in its light alloy head and 8:1 compression. With an 18mm Dell’Orto carburetor, the wet-sump engine produced 7 horsepower at 7,200rpm and drove a 4-speed transmission via helical gears. Sparks and 6-volt lighting were provided by a flywheel magneto.
Performance was competitive for its class with a claimed 63mph top speed while returning around 100mpg. A Sport version followed in 1962 featuring a new cylinder head with revised valve angles in a hemispherical combustion chamber, centrifugal oil filter, higher compression (8.5:1) and a larger 20mm Dell’Orto carb for 8.5 horsepower at 7,500rpm. Equipped with clip-on handlebars, a bum-stop seat and alloy rims, the Sport was good for a claimed 70mph. The standard model, now called Tourismo, continued unchanged.
The Regolarita offroad competition model was introduced for 1962. It made 12 horsepower at 8,000rpm and wore a high-level exhaust, braced high-rise bars and a single seat. The Moto Guzzi factory entered a team of 10 Regolaritas (125cc Stornellos, and 175cc and 250cc Lodolas) in the 1963 International Six Days Trial, taking the International Silver Vase and placing second in the International Trophy class. And while this was the last year of factory support, Stornello Regolaritas were popular with privateer entrants for the rest of the decade. A street version of the Regolarita with lights was produced from 1965 to 1967 in Europe, and sold in the U.S. as the Stornello Scrambler America.
1968 saw the introduction of a 160cc version of the Stornello, with a 58mm bore and 12.6 horsepower at 7,500rpm giving a top speed of 74mph without significantly affecting fuel consumption. But by this time the Stornello’s styling was dated and the 125cc and 160cc engines underpowered. Facing serious competition from domestic rivals like the sporty overhead cam Gilera Arcore 125 and more powerful Japanese competitors, the Stornello range was completely revised for 1971 with more power and a 5-speed transmission. The 125cc version was now good for 12 horsepower, while a new gas tank and bodywork updated the aesthetics. The Stornello continued in this form until Moto Guzzi’s (and Benelli’s) acquisition by Alejandro de Tomaso in 1973.
De Tomaso provided the cash injection Guzzi needed to revamp its range, and the Stornello was replaced by a new 2-stroke 125cc model with more competitive power and a 125cc 4-stroke twin, which would form the basis of the Moto Guzzi/Benelli 254 250cc 4-cylinder. The Stornello name lives on in the new 750cc Moto Guzzi V7 scrambler. MC
1966-1967 Ducati 125 Sport
Years produced: 1966-1967
Power: 10hp @ 7,000rpm
Top speed: 70mph
Engine: 125cc air-cooled OHC single
Transmission: 4-speed, chain final drive
Weight/MPG: 220lb/55-75 mpg (est.)
Ducati’s 125 Sport engine was a direct descendant of the 1955 Gran Sport, albeit with a different cylinder head, enclosed valves and springs, and other detail changes. It also marked the end of the line for Ducati’s “cammy” 125s. The bevel-drive OHC 4-stroke single had a 22mm Dell’Orto carb giving 10 horsepower at 7,000rpm. Drive to the 4-speed transmission was by bevel gears, with sparks provided by a 6-volt generator and battery/coil. An open-cradle single downtube frame supported the drivetrain and ran on 2.5-inch front and 2.75-inch rear tires with SLS drum brakes. The front fork was by Marzocchi with 3-way adjustable twin shocks at the rear. Bodywork included the scallop-sided gas tank and two-tone paint. The result was an attractive, sophisticated and sporty small bike with surprisingly good performance and excellent handling. And with the bulk of Ducati’s singles production from this time in larger capacities, they’re also quite rare. In fact, the 1966-1967 models are absent from Ian Falloon’s Standard Catalog of Ducati Motorcycles) and therefore highly collectible.
1968-1970 Motobi 125 Sport Special
Years produced: 1968-1970 (first series)
Power: 12.5hp @ 8,5000rpm
Top speed: 81mph
Engine: 124cc air-cooled OHV single
Transmission: 5-speed, chain final drive
Weight/MPG: 227lb/90mpg (claimed)
After a spat with his five brothers, Giuseppe Benelli quit the family motorcycle business and started his own company in 1949, initially calling it Moto B Pesaro before finally shortening it to simply Motobi. Five years after his death in 1957, Motobi was absorbed back into the Benelli fold, and Motobis were subsequently often sold branded as Benellis.
The Sport Special was the final development of freelance engineer Piero Prampolini’s distinctive horizontal 4-stroke OHV engine of 1956. Breathing through a 22mm Dell’Orto, the all-alloy unit construction 125cc engine drove a 5-speed gearbox via helical primary gears. The engine hung from a pressed-steel spine frame with telescopic front forks and dual rear shocks running on 2.75 x 18-inch wheels front and rear. The brakes were single-leading-shoe drums, 7-inch front and 5-inch rear.
Motobi 125s were very successful in competition, and the Sport Special inherited their lively performance, enabling it to compete with Gilera’s class benchmark, the Arcore.