Four stroke, single-cylinder, OHC, driven by shaft and
gevel gears, 33 mm inlet valve, 29 mm exhaust valve
Capacity
122 cc / 7.4 cu in
Bore x Stroke
55.5 x 52 mm
Compression Ratio
8.5:1
Cooling System
Air cooled
Lubrication System
Forced oil sump
Induction
Dell'Orto SS1 carburetor
Ignition
Battery and coil
Starting
Kick
Max Power
8.9 kW / 12 hp @ 9800 rpm
Transmission
4 Speed
Clutch
Wet, multi-plate
Final
Drive
Chain
Front Suspension
Hydraulically damped telescopic forks
Rear Suspension
Swingarm, dual shocks
Front Brakes
Drum, Amadori
Rear Brakes
Drum, Amadori
Front Tyre
2.50 -18
Rear Tyre
2.50 -18
Wheelbase
1250 mm / 49.2 in
Dry Weight
85 kg / 187 lbs
Fuel Capacity
16 L / 4.2 US gal / 3.5
Imp gal
Top Speed
150 km/h / 93 mph
When you consider the source, the 1955 Ducati Gran Sport "Marianna"
was a most improbable machine. Two decades earlier, Ducati had been making
radios, not motorcycles. Nine years earlier, in 1946, when Ducati came out
with its first motorbike, it wasn't fierce or outlandish but a cute,
two-horsepower gas-sipper called the "Cucciolo" ("puppy" in Italian).
But, by 1954, an engineer named Fabio Taglioni had
joined Ducati, and his brilliant aesthetic sense combined with his genius
for motor-making transformed the firm into a design and motoring tour de
force. In 1955, the Gran Sport was only a 100cc bike with a four-stroke,
single-camshaft engine, but by late 1956, Taglioni had developed a
triple-camshaft "Desmo" 125cc Gran Premio racing bike capable of a screaming
12,500 rpms--unheard-of revs in those days.
But even before the Gran
Premio, competition had proved the brilliance of the Marianna--so nicknamed
because Taglioni's 1955 design was approved for production during the
Catholic celebration of St. Mary. The Marianna blew away the competition at
its first race and went on to dominate world competitions until the start of
the 1960s. The bike was particularly successful at Milano-Tarantos and also
won at three straight Giro Motociclistico d'Italia (Moto-Giros) endurance
races that ran for five straight days. By the way, although the Gran Sports
never had large displacements, they weighed less than 180 pounds and could
easily run to 120mph. -- Michael Frank