single cylinder
A single-cylinder engine, sometimes called a thumper, is a piston engine with one cylinder. This engine is often used for motorcycles, motor scooters, go-karts, all-terrain vehicles, radio-controlled vehicles, portable tools and garden machinery ...
bevel drive SOHC motorcycle produced by the Italian manufacturer Ducati in 1971 and 1972. Although Ducati had stopped production of the ' narrow case' singles in 1967, the Scrambler used a narrow case engine made by
MotoTrans
MotoTrans is a Spanish company which produced motorcycles and scooters between 1957 and 1983 when it was bought by Yamaha Yamaha may refer to:
* Yamaha Corporation, a Japanese company with a wide range of products and services, established in 188 ...
in Spain. The model was not a sales success with less than 200 sold worldwide and was soon taken out of production.
Technical details
Engine and transmission
The Ducati OHC singles had been designed by
Fabio Taglioni
Fabio Taglioni (10 September 1920 – 18 July 2001) was an Italian engineer.
Born in Lugo di Romagna, he was chief designer and technical director of Ducati from 1954 until 1989. His desmodromic 90° V-twin engine design is still used in al ...
. The initial engines, known as 'narrow case', were superseded by the improved ' wide case' engines in 1967, although the narrow case engines continued to be manufactured by MotoTrans in Spain. The smallest wide case engine was 250 cc and the new 125 Scrambler was fitted with a Spanish made engine. The single cylinder bevel drive OHC engine was of a vertically spilt
unit construction : ''For the vehicle design where the vehicle's skin is used as a load-bearing element, see Monocoque.''
Unit construction is the design of larger motorcycles where the engine and gearbox components share a single casing. This sometimes includes ...
barrels
A barrel or cask is a hollow cylindrical container with a bulging center, longer than it is wide. They are traditionally made of wooden staves and bound by wooden or metal hoops. The word vat is often used for large containers for liquids, u ...
with
austenitic
Austenite, also known as gamma-phase iron (γ-Fe), is a metallic, non-magnetic allotrope of iron or a solid solution of iron with an alloying element. In plain-carbon steel, austenite exists above the critical eutectoid temperature of 1000 ...
liners.
Ball bearing
A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation between the bearing races.
The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads. It achieves this ...
s were used in the
main bearing
Main may refer to:
Geography
* Main River (disambiguation)
**Most commonly the Main (river) in Germany
* Main, Iran, a village in Fars Province
*"Spanish Main", the Caribbean coasts of mainland Spanish territories in the 16th and 17th centuries
...
s and
roller bearing
In mechanical engineering, a rolling-element bearing, also known as a rolling bearing, is a bearing which carries a load by placing rolling elements (such as balls or rollers) between two concentric, grooved rings called races. The relative m ...
s for the
big end
Big or BIG may refer to:
* Big, of great size or degree
Film and television
* ''Big'' (film), a 1988 fantasy-comedy film starring Tom Hanks
* '' Big!'', a Discovery Channel television show
* ''Richard Hammond's Big'', a television show present ...
. Hairspring valve springs were used to close the valves. Bore and stroke were giving a displacement of . Compression ratio was 8.5:1. and claimed power output was @ 8,000 rpm, giving a top speed of .
Fuel was delivered by a 20 mm Spanish built
Amal Monobloc
AMAL was a British engineering company servicing the motorcycle and other light-engineering motor industries between 1927 and 1993carburettor.
Wet sump
Within piston engines, a wet sump is part of a lubrication system whereby the crankcase sump is used as an integral oil reservoir. An alternative system is the dry sump, whereby oil is pumped from a shallow sump into an external reservoir.Wet sum ...
gearbox
Propulsion transmission is the mode of transmitting and controlling propulsion power of a machine. The term ''transmission'' properly refers to the whole drivetrain, including clutch, gearbox, prop shaft (for rear-wheel drive vehicles), differe ...
Unlike other OHC models, the 125 Scrambler used a full duplex cradle frame. Rear suspension was by swinging arm with twin
Marzocchi
Marzocchi is an Italian manufacturer founded in 1949 by brothers Stefano and Guglielmo Marzocchi. The company profile doesn't include hydraulic industrial pumps anymore but only suspension components for motorcycles and bicycles. The Marzocchi Pom ...
telescopic fork
A telescopic fork is a form of motorcycle front suspension whose use is so common that it is virtually universal. The telescopic fork uses fork tubes and sliders which contain the springs and dampers.
The main advantages of the telescopic for ...
s were fitted. Brakes were drums, the front being diameter front and rear. Wire wheels were fitted with a 250x19 tyre front and 350x18 rear.