The Norton Mercury was a

air-cooled Air-cooled engines rely on the circulation of air directly over heat dissipation fins or hot areas of the engine to cool them in order to keep the engine within operating temperatures. In all combustion engines, a great percentage of the heat ge ...

OHV An overhead valve (OHV) engine, sometimes called a ''pushrod engine'', is a piston engine whose valves are located in the cylinder head above the combustion chamber. This contrasts with earlier flathead engines, where the valves were located bel ...

parallel twin A straight-twin engine, also known as an inline-twin, vertical-twin, or parallel-twin, is a two-cylinder piston engine whose cylinders are arranged in a line along a common crankshaft. Straight-twin engines are primarily used in motorcycles; ot ...

motorcycle A motorcycle (motorbike, bike, or trike (if three-wheeled)) is a two or three-wheeled motor vehicle steered by a handlebar. Motorcycle design varies greatly to suit a range of different purposes: long-distance travel, commuting, cruising ...

made by

Norton-Villiers Norton-Villiers was a British motorcycle manufacturer formed in the 1960s following the collapse of AMC. With the general decline of the British motorcycle industry, under a British Government initiative it was later combined with the remnants ...

from 1968 to 1970. It was the last Norton model to use the 'featherbed' frame. Following the collapse of

AMC AMC may refer to: Film and television * AMC Theatres, an American movie theater chain * AMC Networks, an American entertainment company ** AMC (TV channel) ** AMC+, streaming service ** AMC Networks International, an entertainment company *** AM ...

and the subsequent formation of Norton Villiers, the company's focus had been on the new

Norton Commando The Norton Commando is a British Norton-Villiers motorcycle with an OHV pre-unit parallel-twin engine, produced by the Norton Motorcycle company from 1967 until 1977. Initially having a nominal ''750 cc'' displacement, actually , in 197 ...

. There was a large inventory of parts from previous models that would not be used on the Commando, and to use up this stock the Mercury was conceived. The Mercury was introduced in October 1968 and around 750 machines were produced, most of the production going to the US. The model was also used by the

Nigerian Police The Nigeria Police Force is the principal law enforcement and the lead security agency in Nigeria. Designated by the 1999 constitution as the national police of Nigeria with exclusive jurisdiction throughout the country, as at 2016 it has a s ...

Technical details

Engine and transmission

The engine in the Mercury was based on that of the 650SS, which itself was a development of

Bert Hopwood Herbert Hopwood (1908 – 17 October 1996) was a British motorcycle designer. He was, at least, partly responsible for some of the most influential designs for the British motorcycle industry and worked for Ariel, Norton, BSA and Triumph. M ...

's 1948 500 cc twin first used on the Model 7 Dominator. The pre-unit

vertical twin engine used an alloy head that was fed by a single

Amal Concentric AMAL was a British engineering company servicing the motorcycle and other light-engineering motor industries between 1927 and 1993 Primary drive was by chain to a multiplate

wet clutch A clutch is a mechanical device that engages and disengages power transmission, especially from a drive shaft to a driven shaft. In the simplest application, clutches connect and disconnect two rotating shafts (drive shafts or line shafts). ...

and was enclosed in a pressed steel chaincase. The gearbox had 4 speeds. The machine used 12 volt electrics and was charged by a crankshaft mounted

alternator An alternator is an electrical generator that converts mechanical energy to electrical energy in the form of alternating current. For reasons of cost and simplicity, most alternators use a rotating magnetic field with a stationary armature.Go ...

Ignition Ignition may refer to: Science and technology * Firelighting, the human act of creating a fire for warmth, cooking and other uses * Combustion, an exothermic chemical reaction between a fuel and an oxidant * Fusion ignition, the point at which a ...

was by coil and

points Point or points may refer to: Places * Point, Lewis, a peninsula in the Outer Hebrides, Scotland * Point, Texas, a city in Rains County, Texas, United States * Point, the NE tip and a ferry terminal of Lismore, Inner Hebrides, Scotland * Point ...

Cycle parts

The cycle parts of the Mercury were based on the slimline featherbed frame and Roadholder

forks In cutlery or kitchenware, a fork (from la, furca 'pitchfork') is a utensil, now usually made of metal, whose long handle terminates in a head that branches into several narrow and often slightly curved tines with which one can spear foods ei ...

. Unique for this model was a humped dualseat. Brakes were

drum The drum is a member of the percussion group of musical instruments. In the Hornbostel-Sachs classification system, it is a membranophone. Drums consist of at least one membrane, called a drumhead or drum skin, that is stretched over a she ...

front and rear. Most of the production was finished with Atlantic blue oil tank, mudguards and chaincases with a silver petrol tank. It was also available in black with a silver or red tank.

References

Bibliography

External links

* {{Norton motorcycles Norton motorcycles Motorcycles introduced in 1968 Motorcycles powered by straight-twin engines