Английская Википедия:Ducati parallel twins
Шаблон:Short description Шаблон:Use dmy dates Шаблон:Use British English Шаблон:Infobox motorcycle Шаблон:Infobox motorcycle Шаблон:Infobox motorcycle The Ducati parallel twins are a series of Шаблон:Convert and Шаблон:Convert parallel twin SOHC motorcycles produced by the Italian manufacturer Ducati from 1975 to 1981, although 67 Sports Desmos were supplied to Australian importer Frazers in 1983. These were likely built from spares.Шаблон:Sfn The 500cc versions were also produced under licence in Spain by MotoTrans, where production continued until 1983.Шаблон:SfnШаблон:Sfn Sales were poor and the machines were unreliable, earning them the nickname of paralysed twins.Шаблон:SfnШаблон:Sfn
Background
In the early 1970s Ducati were in financial trouble and owned by the Italian Government. In 1972 engineer Cristiano de Eccher was appointed General Manager. De Eccher believed the way to turn the company around was to reduce production costs and sell more machines.Шаблон:Sfn
Ducati's reputation had been built on the OHC. These were now outdated, only offered moderate performance and were expensive to manufacture.Шаблон:Sfn The Japanese were selling a lot of parallel twins and the Ducati management though they could take a share of this market by producing a similar twin.Шаблон:Sfn
Following the success of the 750 GT v twin Ducati chief engineer Fabio Taglioni proposed a smaller v twin with belt driven cams rather than bevel drive of the 750 GT to reduce production costs. De Eccher rejected thisШаблон:Sfn and in a press conference in 1973 announced that the OHC singles would cease production to be replaced with a new parallel twin.Шаблон:Sfn
Engine
Ducati already had a design for a 500 twin. At the request of the American importers, Berliner, Ducati engineer Fabio Taglioni had designed a twin.Шаблон:Sfn The prototype had been shown to American dealers at Daytona in early 1965 but because of poor performance was never put into production.Шаблон:Sfn The prototype was a 360° ohv twin that used dry sump lubrication.Шаблон:Sfn Taglioni declined to develop the engine further and Bruno Tumidei took over the project. Taglioni instead spent his time developing a belt drive OHC v twin, which would later become the Pantah.Шаблон:Sfn
Tumidei extensively updated the engine with ease of manufacture as a primary consideration. The vertically split crankcases and 10° forward canted cylinders were retained. Departing from usual Ducati practices, a forged crankshaft was used running in plain main bearings and big end. No centre main bearing was fitted.Шаблон:Sfn The engine was fitted with a 180° crankshaft to reduce vibration at high speed, although this increased vibration at low and medium speeds.Шаблон:Sfn As the engine was originally designed for a 360° crank with large counterweights, the cranckcases were bulky.Шаблон:Sfn
Converting the engine to OHC, and to keep the engine width to a minimum, the camshaft was driven by chain from the back of the clutch hub via a countershaft behind the cylinders.Шаблон:Sfn The cylinder head was redesigned to use a more modern 60° valve angle as used on the Imola racing bikes.Шаблон:Sfn
To obliviate the need for an external oil tank, a remote reservoir was incorporated within the engine. This resulted in complicated internal plumbing, frequent oil changes and the need for the owner to keep a close eye on oil levels.Шаблон:Sfn
The five speed gearbox was fitted with a left-hand change to comply with American legislation and an electric starter was fitted.Шаблон:Sfn Carburation was by Dell'Orto, Шаблон:Convert on the 500 and Шаблон:Convert on the 350.Шаблон:Sfn
The engine suffered reliability problems, especially oil feed to the camshaft.Шаблон:Sfn Poor build quality also caused reliability problems.Шаблон:Sfn
Models
GTL
A single downtube frame was used the engine as a stressed member.Шаблон:Sfn Marzocchi front forks were fitted. Rear suspension was swinging arm with twin 320 mm Marzocchi shock absorbers.Шаблон:Sfn Ignition was by traditional battery and coil and points.Шаблон:Sfn British Smiths instruments were fitted.Шаблон:Sfn
The machine were styled by Giorgetto Giugiaro, using the same angular styling he used on the 860GT.Шаблон:Sfn
The 500 was fitted with twin Шаблон:Convert disc brakes and a single disc was fitted on the 350. Rear brake was the same Шаблон:Convert drum that had been fitted on the singles.Шаблон:Sfn
Apart from minor changes, such as headlight brackets, the model remained unchanged through its production run.Шаблон:Sfn
Sports Desmo
With sales of the 860GT and twins poor, Franco Zaiubouri replaced De Eccher as Ducati's General Manager in September 1975 and set about reviving the brand.Шаблон:Sfn To make the twins more attractive to buyers, a new model, the 500 Sports Desmo, was planned. Taglioni designed a desmodromic head for the twin. This raised power output to Шаблон:Convert @ 8,500 rpmШаблон:Sfn but gave the machine a narrow powerband.Шаблон:Sfn A number of other small engine changes were made.Шаблон:Sfn
Leopoldo Tartarini of Italjet was engaged to style the new model.Шаблон:Sfn The bike was given a twin downtube frame, a Шаблон:Convert fibreglass racing tank and matching seat. FPS cast wheels and a rear disc brake were also added.Шаблон:Sfn The machine was finished in red and white with a Black exhaust system.Шаблон:Sfn
The 500 Sports Desmo went into production in 1976Шаблон:Sfn and a 350 version, finished in black and yellow,Шаблон:Sfn introduced the following year.Шаблон:Sfn The 350 produced Шаблон:Convert @ 8,500 rpm.Шаблон:Sfn The majority of the Sports Desmos were built at the Italjet factory,Шаблон:Sfn with engines supplied by Ducati.Шаблон:Sfn
GTV
Introduced in 1977, the GTV was essentially a Desmo fitted with a GTL engine. Japanese switchgear, a Bosch headlight, touring handlebars, a chrome exhaust were fitted.Шаблон:Sfn The machine was First shown at the Milan Show in November 1977.Шаблон:Sfn
Production quantities
| Model | 1975 | 1976 | 1977 | 1978 | 1979 | 1980 | 1981 | Total |
|---|---|---|---|---|---|---|---|---|
| 500 GTL | 447 | 285 | 373 | - | - | - | - | 1,105 |
| 350 GTL | 530 | 400 | - | - | - | - | - | 930 |
| 500 Sport Desmo | - | 441 | 1,184 | ? | 130 | ? | 172 | ?Шаблон:Efn |
| 350 Sport Desmo | - | - | 456 | ? | ?Шаблон:Efn | ? | ? | 1,166 |
| 500 GTV | - | - | 453 | ? | ? | ? | ?Шаблон:Efn | 700 |
| 350 GTV | - | - | 360 | ? | ?Шаблон:Efn | ? | ?Шаблон:Efn | 958 |
| Total | 977 | 1,126 | 2,826 | 1,610 | ? | ? | ? | |
| References:Шаблон:SfnШаблон:SfnШаблон:Sfn | ||||||||
Exports
A few 500 GTL models were exported to the US.Шаблон:Sfn
Around 500 Sports Desmos were exported to the UK, and slightly more than this to France.Шаблон:Sfn
208 500 GTLs, 224 Sport Desmos and 36 GTVs were exported to Australia.Шаблон:Sfn
References
Bibliography
- Шаблон:Cite magazine
- Шаблон:Cite magazine
- Шаблон:Cite web
- Шаблон:Cite magazine
- Шаблон:Cite journal
- Шаблон:Cite book
- Шаблон:Cite book
- Шаблон:Cite web
- Шаблон:Cite book
- Шаблон:Cite book
- Шаблон:Cite magazine
- Шаблон:Cite book
- Шаблон:Cite book
- Шаблон:Cite web
- Шаблон:Cite journal
- Шаблон:Cite web
External links
