| MV Agusta 175 | |
| Manufacturer: | MV Agusta |
| Predecessor: | 1953-1960 |
| Class: | Touring GT (Gran Turismo) Sports Supersports Production racer Racer |
| Engine: | 175 cc Four-stroke single-cylinder |
The MV Agusta 175 were a series of motorcycles produced by the Italian manufacturer MV Agusta from 1953 to 1960. The series included touring, GT (Gran Turismo), sports and supersports models. There were also two racing variants. Because of the shape of the petrol tank, the sports and supersport models became known as the Disco Volante (Flying Saucer).[1] The series was MV's best seller.
The MV Agusta 175 was launched at the EICMA (Milan Motorcycle Show) in 1952,[2] with production starting in 1953. For MV Agusta, this motorcycle was a milestone. It was their first production machine with a four-stroke engine. The unit construction single-cylinder engine was designed with an overhead camshaft for high performance. The chain-driven camshaft operated the valves via rocker arms, which were closed by hairpin valve springs. The engine was inclined forward at 10° and manufactured in alloy and a bore and stroke of 59.5 mm × 62 mm.
The cycle parts featured an advanced duplex frame that used the engine as a stressed member, telescopic forks, a swinging arm and full-width alloy hubs.[3]
The machine was initially available as a tourer, the 175 CST/CSTL, which produced 8bhp at 5600 rpm. A sports model, the 175 CS, was soon introduced. This model featured a larger carburetor and produced 11bhp at 6700 rpm, which put the machine above similar models from other manufacturers. The 15 bhp supersport model, the MV Agusta 175 CSS, was introduced at the 1954 Milan Show and, and, unlike the touring and sports versions, was fitted with Earles forks; it was priced at 280,000 lire.
A pushrod version of the engine was introduced in 1957. It was hoped that a simpler, cheaper model, albeit with less power, would appeal to a larger audience. Pushrod models had an AB suffix to the model designation.[4]
The 175 CST was one of the original models produced. This touring model had a frame of a double loop design using tubes for the front sections and pressed steel members at the real. Suspension was telescopic forks at the front and a swinging arm at the rear and the wheels were 17" diameter. Separate saddles were used for the rider and passenger. The 175 cc OHC engine produced 8bhp at 5600 rpm, giving a top speed of 60 mph (100kmh).[5]
The 175 CSTL, also known as the Turismo Lusso, was another touring model, but had larger, 19" wheels than the CST and a "long seat" (dualseat) fitted rather than separate saddles.
The sports model 175 CS was introduced in 1953. It featured lower handlebars and a more sporty riding position. The engine featured a larger 22 mm carburettor and the engine produced 11bhp at 6700 rpm, giving a 70mph top speed. About 4,500 examples of this model were made.[6]
The Italian motorcycle fans connected the shape of the fuel tank with a "vehicle from another galaxy", which gave the MV Agusta 175 CS its nickname, Disco Volante (Flying Saucer), which was also adopted in the model history of the manufacturer.
The CS model was also produced under licence in Spain by Avello.[7]
An updated version on the 175 CS was introduced in 1957. The 175 CS 57 featured dynamo ignition and a revised exhaust.[8]
In July 1954, the supersport model 175 CSS was introduced. The engine was further turned from the CS model, including higher compression ratio and a larger carburettor, to produce 15bhp @ 8,800 rpm. Cycle parts were the same as the CS model, except it was fitted with Earles forks. The petrol tank of the CS was retained, so this model was also known as the Disco Volante.[9] This is the rarest model of the series, only around 500 of this model was produced.
The 175 CSGT, also known as the Turismo Monoalbero, was only manufactured in 1957. It was an upscale GT (Gran Turismo) version of the CS model. Although the engine was from the CS, the cylinder head was from the CSTL model, which reduced power.[10]
Introduced in 1957, it was hoped that these simpler, cheaper models would appeal to a larger audience. Various trim levels were offered: Economica, Turismo, America and America Lusso.[11] All used a pushrod version of the engine, which produced 8bhp @ 5,200 rpm, giving a top speed of 60 mph (100kmh).
An enlarged version of the 175 AB was introduced in 1959. The pushrod engine's bore was increased to 69 mm to give a capacity of 232 cc.[12] Except for the colour of the petrol tank, visual differences between the 175 and 235 models were minimal.[13] Sales were slow as most buyers wanting a larger machine than 175 preferred the "full" 250 cc of the 250 Raid. Production stopped in 1961.[14]
A variant was also manufactured under licence in Spain by Avello, where it was marketed as the 235 Deva.[15]
The 175 cc Formula Sport Derivata race series was very popular in Italy. MV Agusta designed the 175 CSS-5V for this race series using the production engine. The Squalo (shark), as it was generally known, had a lighter frame based on that used on the works racers, larger brakes, a magneto, Earles forks and a five-speed gearbox. It was sold as an over the counter racer and riders such as Bob Keeler, Derek Minter and Mike Hailwood used the Squalo in national competitions.[16] Hailwood won his first ever race on one of these machines bored out to 196 cc in a 200 cc class race at Oulton Park in 1957.[17] Around 200 of the model were manufactured between 1954 and 1957.[18]
A street version of the Squalo was offered fitted with headlights and mufflers.
The 175 Bialbero was an enlarged version of the successful DOHC 125 Bialbero works racer. The bore was increased to 64 mm to give a capacity of 174 cc and had a power output of 25 bhp at 11,500 rpm. The machine was produced in response to Moto Morini and Mondial entering the 175 cc class with their racing machines.[19]
The machine won 12 races in total, the first being by Carlo Ubbiali at the Circuit of Perugia on 22 August 1954. Umberto Masetti won the 175 cc Italian Championship in 1955 on a Bialbero. The machine was placed first and second in the 1957 Motogiro (Motorcycle Tour of Italy).
| MV Agusta 175 models | CST[20] | CSTL | CS[21] CS 57 | CSS[22] | CSGT | AB[23] | CSS-5V[24] | Bialbero[25] | 235 Tevere | |
|---|---|---|---|---|---|---|---|---|---|---|
| Year | 1953-1957 | 1954-1958 | 1955-1958 | 1957 | 1957-1959 | 1954-1960 | 1954–1958 | 1959-1961 | ||
| Valvetrain | OHC | OHV | OHC | DOHC | OHV | |||||
| Engine configuration | Four-stroke single-cylinder engine | |||||||||
| Engine cooling | Air cooling | |||||||||
| Bore | 59.5 mm | 63 mm | 69 mm | |||||||
| Stroke | 62 mm | 56 mm | 62 mm | |||||||
| Engine displacement | 172 cc | 174 cc | 232 cc | |||||||
| Lubrication system | Wet sump | |||||||||
| Carburetor | Dell'Orto 18 mm | Dell'Orto 22 mm | Dell'Orto 25 mm | Dell'Orto 20 mm | Dell'Orto 18 mm | Dell'Orto 25 mm | Dell'Orto 25 mm | |||
| Compression ratio | 6.5:1 | 7:1 | 9:1 | 6.5:1 | 9:1 | 9.5:1 | 7.2:1 | |||
| Max power | 8 bhp ( kW) @ 5,200 rpm | 11bhp @ 6,700 rpm | 15bhp @ 6,700 rpm | 8 bhp ( kW) @ 5,200 rpm | 16bhp @ 8,800 rpm | 25bhp @ 11,500 rpm | 13bhp @ 5,500 rpm | |||
| Top speed | 60 mph (100 kmh) | 70 mph (115 kmh) | 85 mph (135 kmh) | 60 mph (100 kmh) | 95 mph (150 kmh) | 110 mph (180 kmh) | 65 mph (105 kmh) | |||
| Primary drive | Gears | |||||||||
| Clutch | ||||||||||
| Gears | 4 | 5 | 4 | |||||||
| Final drive | Chain drive | |||||||||
| Frame | Double cradle | |||||||||
| Front forks | Telescopic forks | Earles forks | Telescopic forks | Earles forks | Telescopic forks | |||||
| Rear forks | Swinging arm | |||||||||
| Rear suspension | Coil springs with hydraulic shock absorbers | |||||||||
| Brakes | Drum brakes | |||||||||
| No. produced | 6,500[26] | 9,500[27] | 5,000 | 500 | 500[28] | 6,000[29] | Unknown | 1,000 | ||
