Ducati singles
The Ducati singles were single cylinder motorcycles, made by Ducati from 1950 to 1974. Chief Engineer Fabio Taglioni developed a desmodromic valve system in these years, a system that opens and closes the valves using the camshaft, without the need for valve springs. This valve system has become a trademark feature of Ducati motorcycles.
In 1926, the brothers Adriano and Marcello Ducati founded Societa Scientifica Radio Brevetti Ducati, a company in Bologna producing tubes, condensers and other radio components. On June 1, 1935, the cornerstone of a factory in Borgo Panigale was laid. By 1940, the company was engaged in the manufacture of electronic equipment for the military, making the factory a target for Allied bombing. The Ducati factory at Borgo Panigale was hit badly more than once, but maintained production.
Cucciolo
During World War II, Aldo Farinelli, a lawyer from Turin, developed with the Italian Society of Auto-Aviator Technical Applications a small engine to be mounted on a bicycle, called the Cucciolo, by 1945. The weight of the engine was less than 8 kg. In 1950 Ducati began producing its own complete 98-pound motorcycle with the same name. The production at Ducati went on until 1958.Ducati 65 TS and Cruiser
The first 4 stroke Single was the Ducati 60.The market was moving though, towards bigger motorcycles and Ducati's IRI management felt diversification was the only answer. Ducati made an impression at the early 1952 Milan Show, introducing the Ducati 65 TS cycle and the Cruiser, the world's first four-stroke scooter. Despite being described as the most interesting new machine at the 1952 show, the Cruiser was not a great success. A couple of thousand were made over a two-year period before being withdrawn from production.
In 1953, management decided to split the operation into two separate entities, Ducati Meccanica SpA, and Ducati Elettronica SpA, under separate management. Dr. Giuseppe Montano took over as head of Ducati Meccanica SpA and the old Borgo Panigale factory was modernized, with government assistance.
By 1954, Ducati Meccanica SpA was producing 120 bikes a day, but cheap cars were entering the markets, and sales for many motorcycle manufacturers would decline.
OHV pushrod singles
From the mid-1950s through mid-1960s Ducati produced non-Taglioni-designed OHV singles with conventional pushrod valve operation, such as the 125 Bronco.Two-strokes
Ducati was manufacturing a 50 cc two stroke, with power outputs from 0.92 hp at 4,600 rpm to 4.2 at 8,600 rpm. Some attempts were made to race these 50 cc Ducati two-strokes in Europe, but the 3 speed gearbox and lack of power compared to makes such as Itom meant that there was no success. They also failed to sell in America, their target market, as the US demand just did not exist. Fairly large quantities were sold in Europe and for some years it was the sales of two-strokes that kept the company afloat. In hindsight, Ducati probably would have done better by focussing on its well-developed line of sporting four-strokes, but the company persisted with 50 cc, 80, 90, and finally 100 cc versions of the same two-stroke bikes, despite falling sales. These small 2 strokes were built in all sorts of versions, from mini-racers through trail and scrambler type models even to scooters. Early versions had 3-speed hand change gears but this later became 4-speed foot change. Some versions had fan-cooled engines. While sufficient members of management wished to persist in production, some engineers were already refusing to work on them, and pursuing other company projects with more promise for the company future.In 1977, Ducati made their last significant attempt to provide a competitive 'off-road' two stroke motorcycle. The 125 'Regolarita' was a 6 speed enduro model based on an ISDT factory prototype from 1975. While the bike proved viable enough overall, gearbox problems plagued it during development and the project was terminated in 1978. Ducati were sufficiently serious about this project to explore MX versions. However like the parallel twins developed and produced at that time, they were sidelined in favour of Ducati's focus on evolutions of their now established and popular V twins.
OHC singles
Engines
The Taglioni designed single cylinder bevel drive OHC engines were of a vertically spilt unit construction and had alloy head and alloy barrels with austenitic liners. Ball bearings were used in the main bearings and roller bearings for the big end. Hairspring valve springs were used to close the valves except on the 239 cc models. Wet sump lubrication was used.Narrow case
The earlier engines were retrospectively known as 'narrow case' after the introduction of the revised 'wide case' engines.Type A
First shown at the Milan Motorcycle Show in late 1956, the OHC singles were available in 100, 125, 175 and 200 cc variants. Production of the Type A continued until 1961.Type B
With the introduction of the 250 cc Monza and Diana, the engines were revised with improvements to the crankshaft, cylinder head and clutch housings. The Type B engines were available in 125, 160, 200, 250 and 350 cc displacements. In 1964 5 speed gearboxes were fitted.Wide case
In 1968, an improved engine was introduced based on the engines used in the 250SCD and 350SCD racers. It featured rear engine mountings that were three times wider than the front engine mount. Internally the engine had stronger main bearings and big ends, an improved kickstart mechanism and larger capacity sump. The engine continued until production of the OHC stopped in 1974 and was available in 239, 250, 350 and 450 cc versions.Desmo
The wide case engines were also available in desmo versions. Unlike the racing models, the road versions used a single camshaft and used helper valve springs to improve starting and low speed running. Apart from the cylinder head assembly, the desmo and non-desmo engines are the same.OHC 98 cc Gran Sport
Ducati's single overhead-cam 98 cc Gran Sport, designed by Taglioni, became the blueprint for all future Ducati singles. It had an air-cooled cylinder inclined forward 10 degrees from vertical, gear primary drive, wet-sump lubrication, battery ignition and camshaft drive by vertical shaft and bevel gears. This bike came to dominate its class in Italian racing. In 1956 there was a DOHC 125 cc version of the Gran Sport.In spite of being a government appointed director, Montano was a motorcycle enthusiast and under his direction, Ducati's competitive activities grew. Fabio Taglioni was chief designer and technical director of Ducati from 1954 to 1989, serving longer than many of the managements that were to follow. The company soon developed a full-fledged racing team. Italians were avid racing fans and would buy bikes built by winners. To acquire a competitive image Ducati needed to race successfully. Taglioni's usual development procedure was to test a motorcycle on the racetrack before releasing it to the public.
125 Desmo Ducati
The high RPMs needed to produce competitive power in a small engine generated valve float, which Taglioni believed could be overcome with desmodromic valve actuation. The 125 Grand Prix could produce 16 hp at 11,500 rpm, its true rev limit, while the Desmo could crank out 19 hp at 12,500 rpm and could “safely” rev further to 15,000. Big-end life was short at these sorts of revs and new crankshaft bearings were put in for every race.Desmodromics, were used in the W196 Mercedes-Benz straight-eight Desmo engines that dominated early formula 1 racing. When Mercedes retired from racing, it retired the Mercedes desmo technology, never using it in production models. Taglioni applied it successfully to Ducati motorcycles. As usual, Desmo technology was used first in racing Ducatis and then in Ducati street machines.
The 125 Desmo Ducati won its first race at the 1956 Swedish G.P. at Hedemora, lapping all the other cycles, but then its rider, Gianni Degli Antoni, died during the practice for the next race, the Italian G.P. of Monza. That death dealt a severe blow to the Ducati racing program and it was not until 1958 that their team was able to mount a serious challenge to Italy's MV Agusta, and their top rider, former 125 cc world champion, Carlo Ubbiali.
In 1958 the Ducati Desmo dominated the racing season and the racing team was soon headed for the World Championship. Unfortunately a mid-season injury to winning Ducati rider Bruno Spaggiani spoilt their run, allowing Ubbiali to narrowly take the title again. Nevertheless, in that season the Desmodromic engine had proved its quality and reliability, in terms of maximizing engine power and as insurance against over-revving damage. These characteristics proved attractive to motorcycle buyers.
The 125 Sport became the 125 Monza. There was also the Monza Super, a further improved version with high-compression piston, modified camshaft, a slightly larger SS1 Dell'Orto racing carburettor, and a straight-through exhaust. The Monza Super was British market only. Oxford's Ducati dealer, Kings, was pushing Ducati for a 250 cc machine to compete against British and Japanese motorcycles.
Ducati began by building a 250 cc racer. The prototype won most of its races in America, many running in conjunction with 500 cc events.
In 1959 Ducati introduced the 200cc Elite and 200SS, which were derived from the very successful 175cc single cylinder shaft driven ohc machine.