A look back at MV Agusta history focusing on 750 S

MV Agusta 750S

With Ian Fallon

Although Ducati is currently the most successful Italian racing brand, it is sometimes forgotten that during the 1960s and early 1970s, MV Agusta was almost unbeatable in the 500 cc class.

Their proof is in a total of 38 Individual Drivers’ World Championships and 37 Manufacturer’s World Championships over a 25-year period from 1952 to 1976.

During that time, MV won 270 races at the World Championships, an incredible feat that is unlikely to be repeated again and resulted in a limited number of hand-built street bikes. ; topped by the magnificent 750 S.

The founder of Agusta, Count Giovanni Agusta, built his first airplane in 1907, just four years after the Wright brothers. After the war, his son Count Domenico Agusta founded MV Agusta as a motorcycle company and was president until his death in 1971.

The first MV Agusta motorcycle produced in 1946, was a two-stroke, 98 cc engine, called a Vespa, or wasp. This led to a series of smaller models, and throughout the 1950s, MV Agusta was the leading manufacturer of basic motorcycles.

With the agreement to build Bell helicopters under license in 1952, Agusta became Italy’s leading helicopter manufacturer, which provided income for Domenico to participate in a motor racing program. expensive.

The first four-cylinder MV Agusta street bike appeared in prototype form in the late 1950s, less than a year after the 500cc four-cylinder race bike made its debut. In 1949, Count Agusta persuaded engine designer Piero Remor to leave Gilera and the new engine was virtually identical to Gilera’s design.

For a distinctive look and to avoid liability, the MV Agusta four race car was the first to feature a shaft drive system and torsion bar suspension, features that also appeared on the R19 Turismo prototype.

The R19 was never produced but by 1966 Honda posed a threat in the 500cc Grand Prix and MV Agusta replaced their venerable four-wheeler with a more compact three-wheeler. Instead of wasting the production facility, Count Agusta then decided to offer these four as an expensive limited edition street bike.

This time it’s a 600 cc version of the same engine that produces 52 hp at 9,000 rpm. Weighing 221kg and equipped with a final bearing, the 600 was created as a touring machine so customers didn’t want to turn it into a four-cylinder MV racer. The 600 is also extremely ugly, the front being highlighted by large rectangular Fiat car headlights.

Despite the rather unfortunate styling, the 600 is a rather innovative machine. Not only is it one of the first on a four-wheel chassis, it also includes an electric starter and a pair of cable-operated front Campagnolo dual disc brakes.

Such an expensive and characteristic machine (every buyer was entitled to spend a week at the factory learning how to drive and maintain it) had a very limited market, and in 1970 the sportier 750 S was sold. replace it. This time around, the MV has more than just the right styling, and despite the shaft drive, the 750 cc engine delivers real performance.

The 750 S is essentially a boring 600 (65 x 56mm) but with bright new colors and a sculpted fuel tank that looks significantly sportier. The engine, essentially the old 500 cc Grand Prix 4 from the 1950s, dominated the 750 S and while it seemed massive and brutal at first, when viewed up close, the individual components were a complex, almost subtle feature. Inside it is a precision casting masterpiece, gears, needles and bearings.

A trio of matching straight-cut gears running between the inner cylinders drive the dual overhead camshafts, while the pressed-together crankshaft runs in ball bearings and is held in a separate cylinder block sub-assembly. screw into the mold of the main motor. Following on from MV racing practice, this not only supports the crankshaft but also eliminates the need for complex and complex machining/casting operations for such a limited production engine.

While other production four-cylinder engines hang the alternator and ignition points at either end of the crankshaft, the widest part of the MV engine is the outboard cylinders. The Bosch automotive starter alternator is mounted behind the engine compartment with the Bosch automotive igniter of the contact breaker and the distributor. With four Dell’Orto UB24mm carburetors and a 10:1 compression ratio, power increases to 66 hp at 8,000 rpm.

The chassis is also improved compared to the 600 and the Grimeca 230 mm dual drum brakes at the front replace the less efficient mechanical discs. Suspension consists of 35 mm Ceriani front forks and Sebac shock absorbers, while the wheels are 18-inch Borrani.

The wheelbase is short at 1,390mm, but with a dry weight of 235kg, the 750 S is still very heavy, mainly due to the sand-cast engine crankcase and cylinder head (because of low production), and the final transmission shaft. .

The rear-wheel drive’s springless weight has a detrimental effect on handling, while the short wheelbase and heavy upper feel give the 750 MV a unique feel. As a result, the Fours MVs never possessed the poise like their counterparts from other Italian races and were unsuccessful in production races.

Sydney dealer Brian Clarkson took part in an MV Agusta 750 S in the 1972 Castrol six-hour race, but retired half-way through due to clutch malfunction – the car smoked heavily when accelerating just before retirement. Clarkson also drove the 750 S at Bathurst in 1973, finishing sixth in the Chesterfield 5000.

For 1974, the 750 S was updated with hotter cams, larger valves and four Dell’Orto 27mm square slide carburetors. Power goes up to 69 hp at 8,500 rpm. Although the chassis remains the same as before, the Scarab discs have replaced the previous Grimeca front drum brakes.

In 1975, the 750 America replaced the 750 Sport but because they were so expensive many remained unsold for several years. The last production four-cylinder MV Agusta was the 1977 Monza 850.

The MV Fours may have been flawed and damaged in the making, but the soul of these motorcycles is the great engine. While offering a connection to the racing past, it also remains one of the most sophisticated, complex and beautiful engines ever to grace a street bike.

No other motorcycle engine can reproduce the sound and experience of the four-cylinder MV howl and a ride that can forgive the weaknesses of a flawed chassis.

Specifications MV Agusta 750 S