MV Agusta 250 Monocilindrica Bialbero

MV Agusta

Company type	Private
Industry	Motorcycle manufacturing
Founded	January 1, 1945 (1945-01-01)
Founder	Count Domenico Agusta
Headquarters	Varese , Italy
Products	Motorcycles
Website	www.mvagusta.com

The MV Agusta 250 Monocilindrica Bialbero was a factory racing motorcycle with a displacement of 250 cc, produced by the Italian manufacturer MV Agusta between 1956 and 1959. This model achieved notable success, securing victory in 15 Grand Prix events, winning two rider World Championships, as well as two constructors' World Championships.

Evolution

In the late 1940s, MV Agusta began competing in Grand Prix motorcycle racing focusing initially on the 125 cc and 500 cc categories. Engineer Piero Remor developed the 125 "Bialbero" twin-cam engine for the lightweight class. This engine was later enlarged to a 175 cc capacity, responding to the popularity of that category within Italy, where most leading manufacturers offered production racers. Subsequently, this powerplant was further bored out to just over 200 cc, enabling MV Agusta to enter the 250 cc division in 1955 with the MV Agusta 203 Bialbero. Shortly after its debut, the displacement was increased again to 220 cc. Riding this machine, Bill Lomas completed the 1955 Grand Prix motorcycle racing season, finishing third overall in the World Championship standings. That year, MV Agusta also secured the manufacturers' championship. In order to develop a true 250 cc racer by 1956, increasing bore size was no longer feasible; thus, the stroke was extended from 56 mm to 60 mm to reach the desired displacement.

Technical

The motorcycle featured an air-cooled, single-cylinder, four-stroke engine equipped with dual overhead camshafts (DOHC). These camshafts were driven through a gear train. The valves were positioned at a 90° angle relative to one another and were closed by hairpin valve springs. The engine's bore measured 72.6 mm, while the stroke was 60 mm, resulting in an overall engine displacement of 248.2 cc. Fuel delivery was managed by a Dell'Orto SS 25 A carburetor.

Power transmission involved a wet multi-plate clutch actuated via gears connected to the crankshaft. The gearbox offered five speeds, and the rear wheel received drive through a chain.

The chassis consisted of a double cradle frame constructed from 25 mm diameter × 1.2 mm thick chrome molybdenum (41xx steel) tubing. Suspension components included a telescopic fork at the front and a rear swingarm equipped with hydraulic shock absorbers.

Results

During the 1956 season, this motorcycle achieved significant success in the Grand Prix championship. Carlo Ubbiali secured victories in five out of six races, although he retired after setting the fastest lap at the Ulster Grand Prix. Ubbiali ultimately claimed the world title, with fellow MV Agusta rider Luigi Taveri finishing as runner-up. MV Agusta's dominance in the 250cc category was partly due to limited competition from other manufacturers. For instance, Moto Guzzi, represented by Enrico Lorenzetti who placed third, had ceased development on their 250 Bialbero model in 1955. Meanwhile, NSU, with Horst Kassner placing fifth, withdrew its factory team after the fatalities of Rupert Hollaus and Gustav Baumm; Kassner competed on an NSU Sportmax production racer. Machines from ČZ lagged behind Western competitors, with František Bartoš finishing only twelfth.

In 1957, MV Agusta faced increased challenges as Mondial returned with their 250 Bialbero and two prominent riders: former 125 cc Champion Cecil Sandford and the promising young talent Tarquinio Provini. The season began strongly for MV Agusta; Carlo Ubbiali won the opening Grand Prix at the Hockenheimring, followed by teammate Roberto Colombo in second place. At the Lightweight TT, Sandford claimed victory while Taveri and Colombo took second and third respectively; Provini recorded the fastest lap, although both he and Ubbiali retired from the race. Notably, MV Agusta did not participate in the event at Assen, where Provini triumphed ahead of Sandford and Sammy Miller. Colombo competed only in the 125cc category there, finishing second. Tragically, Colombo died during practice at Spa-Francorchamps riding an MV Agusta 350 4C racer. Following this loss, MV Agusta withdrew from the 250 cc class for the remainder of that year. Nonetheless, John Hartle continued to race an experimental twin-cylinder MV Agusta at Spa and secured a victory. Colombo was posthumously recognized as MV’s top 250 cc rider that season, finishing fourth overall in the championship standings ahead of Ubbiali.

The latter part of 1957 marked a pivotal moment for international road racing when all major Italian manufacturers—Mondial, Moto Guzzi, Gilera, and MV Agusta—collectively exited the World Championships due to escalating costs that outweighed commercial benefits. This was especially impactful for Moto Guzzi and Gilera whose revenues depended solely on motorcycle sales; Mondial supplemented income through transport tricycles, while for Agusta motorcycle production remained more of a passion project than a core business. However, Count Domenico Agusta reconsidered and resumed racing efforts. By 1958, MV Agusta stood as the sole leading factory team competing globally, attracting elite riders such as John Surtees and John Hartle in the 350 and 500 cc divisions alongside Tarquinio Provini and Carlo Ubbiali in the 125 cc and 250 cc categories. Provini dominated by winning four of six races to clinch the world championship decisively, also securing the Constructors Championship for MV Agusta.

Although privateers continued to race this model during the 1959 season, factory riders transitioned to the newer MV Agusta 250 Bicilindrica machine—on which John Hartle had previously achieved victory in Belgium during 1957.

Bibliography

• Cook, R.A.B., ed. (1956). Motor Cycling Sports Yearbook 1956. Temple Press Ltd.
• Cook, R.A.B., ed. (1957). Motor Cycling Sports Yearbook 1957. Temple Press Ltd.