Matchless G80
Encyclopedia
The Matchless G80 was a single cylinder 500 cc British motorcycle built by Associated Motorcycles (AMC) between 1946 and 1966. During the 1950s and 1960s, the main export product for AMC was the AJS
/Matchless
range – the road bikes were very similar, often with only the badges distinguishing one marque from the other; the equivalent AJS being the Model 18
.
s were still pushrod singles. The Matchless G80 is typical of this era. The earliest G80 is sometimes referred to as a G80L, the L signifying "Teledraulic" forks, rather than girder forks.
The magneto on an AJS was in front of the cylinder, and the Matchless magneto was behind.
A design originating in the 1930s, the Matchless was updated with a spring frame (swingarm) rear suspension in 1949, becoming the G80S. The suspension was a vast improvement on the bouncy rigid rear end but wheel travel was limited.
AMC had adopted Velocette
's twin-shock swingarm
rear suspension design for its top models. Vertical shock absorber
units were introduced in 1949. The initial "Candlestick" shocks held only 50 cc of SAE 20 weight oil. Leak prone, they were replaced by the "Jampot" shocks in 1951, and by Girling shocks in 1956. In 1957, AMC switched from Burman
gearboxes to their own make.
The leaky pressed-steel primary chain-case first appeared on AMC machines in the 1930s. In 1958 an alloy cover primary chain-case became available.
of 5.9:1, because of the poor quality fuel available in the United Kingdom immediately after the Second World War. In 1949 the hairpin valve springs were back, after the use of conventional coil valve springs in wartime engines. By 1951 the G80 had an alloy cylinder head and the barrel fins now went all the way to the base on competition models. The compression ratio was increased to 7.3:1 in 1956.
Low compression meant that it was easy to kick-start
and was more flexible at low revs. The earlier long stroke version might not quite reach 80 miles per hour (35.8 m/s), but it could trundle along at less than 20 miles per hour (8.9 m/s) in top gear. It also gave good fuel economy.
Matchless also made a 600cc version of the G80 called Typhoon. The bore was increased to 89mm while the stroke was increased from 85.5mm to a whopping 96mm. 125 bikes were reportedly made and almost all of them were sold in the USA. There was a road model with lights and a competition model without lights. The engine prefix code was TCS on these bikes.
Engine numbers usually start with the year of production, followed by model designation, and completed with the production number of the motorcycle.
AJS
AJS was the name used for cars and motorcycles made by the Wolverhampton, England, company A. J. Stevens & Co. Ltd, from 1909 to 1931, by then holding 117 motorcycle world records, and after the firm was sold the name continued to be used by Matchless, Associated Motorcycles and Norton-Villiers on...
/Matchless
Matchless
Matchless is one of the oldest marques of British motorcycles, manufactured in Plumstead, London, between 1899 and 1966. A wide range of models was produced under the Matchless name, ranging from small two-strokes to 750 cc four-stroke twins...
range – the road bikes were very similar, often with only the badges distinguishing one marque from the other; the equivalent AJS being the Model 18
AJS 18
The AJS 500cc Model 18 and AJS Model 18S are 500 cc British motorcycles almost identical to the Matchless G80 and both were produced in the same Associated Motor Cycles London factory from 1945 to 1966...
.
Development
In the early 1950s, the most popular British four-strokeFour-stroke cycle
A four-stroke engine, also known as four-cycle, is an internal combustion engine in which the piston completes four separate strokes—intake, compression, power, and exhaust—during two separate revolutions of the engine's crankshaft, and one single thermodynamic cycle.There are two...
s were still pushrod singles. The Matchless G80 is typical of this era. The earliest G80 is sometimes referred to as a G80L, the L signifying "Teledraulic" forks, rather than girder forks.
The magneto on an AJS was in front of the cylinder, and the Matchless magneto was behind.
A design originating in the 1930s, the Matchless was updated with a spring frame (swingarm) rear suspension in 1949, becoming the G80S. The suspension was a vast improvement on the bouncy rigid rear end but wheel travel was limited.
AMC had adopted Velocette
Velocette
Velocette is the name given to motorcycles that were made by Veloce Ltd, in Hall Green, Birmingham, England. One of several motorcycle manufacturers in Birmingham, Velocette was a small, family-owned firm, selling far fewer hand-built motorcycles than the giant BSA, Norton or Triumph concerns...
's twin-shock swingarm
Swingarm
A swingarm, or "swinging arm" is the main component of the rear suspension of most modern motorcycles and ATVs...
rear suspension design for its top models. Vertical shock absorber
Shock absorber
A shock absorber is a mechanical device designed to smooth out or damp shock impulse, and dissipate kinetic energy. It is a type of dashpot.-Nomenclature:...
units were introduced in 1949. The initial "Candlestick" shocks held only 50 cc of SAE 20 weight oil. Leak prone, they were replaced by the "Jampot" shocks in 1951, and by Girling shocks in 1956. In 1957, AMC switched from Burman
Burman and Sons Ltd
Burman and Sons Ltd, of Ryland Road, Birmingham, England, manufactured Burman-Douglas steering gear.Their recirculating worm and ball design of steering gear was fitted to pre-war vehicles such as the Ford Eight and the Ford Prefect, the Bedford CA, plus many other vehicles - both pre and post-war....
gearboxes to their own make.
The leaky pressed-steel primary chain-case first appeared on AMC machines in the 1930s. In 1958 an alloy cover primary chain-case became available.
Engine
The motor was released with a compression ratioCompression ratio
The 'compression ratio' of an internal-combustion engine or external combustion engine is a value that represents the ratio of the volume of its combustion chamber from its largest capacity to its smallest capacity...
of 5.9:1, because of the poor quality fuel available in the United Kingdom immediately after the Second World War. In 1949 the hairpin valve springs were back, after the use of conventional coil valve springs in wartime engines. By 1951 the G80 had an alloy cylinder head and the barrel fins now went all the way to the base on competition models. The compression ratio was increased to 7.3:1 in 1956.
Low compression meant that it was easy to kick-start
Kick start
Kick start refers to a method of starting an internal combustion engine by pushing a ratcheting lever with one's foot. Kick start mechanisms were almost universally a part of motorcycle engines before the mid-1970s, and were phased out of production over the next twenty years or so as electric...
and was more flexible at low revs. The earlier long stroke version might not quite reach 80 miles per hour (35.8 m/s), but it could trundle along at less than 20 miles per hour (8.9 m/s) in top gear. It also gave good fuel economy.
Model variations
The 500 cc "long stroke" G80CS was produced from 1951 through 1955. In 1956 it was replaced by the shorter stroke, larger bore models that used the same numeric codes. The bore of these early G80CS's was 82.5 mm (3.25"), while the 1956 through 1966 “short stroke” (final version) models had a bore of 86 mm. The C is for Competition (Scrambles) and the S for Suspension (not a rigid rear frame).Matchless also made a 600cc version of the G80 called Typhoon. The bore was increased to 89mm while the stroke was increased from 85.5mm to a whopping 96mm. 125 bikes were reportedly made and almost all of them were sold in the USA. There was a road model with lights and a competition model without lights. The engine prefix code was TCS on these bikes.
Engine numbers usually start with the year of production, followed by model designation, and completed with the production number of the motorcycle.