Matchless G80
Matchless G80 Background & History
The Matchless G80 was a 500cc single-cylinder 4-stroke motorcycle that was in production from 1946 through the 1966 model year. Throughout the 1950s and 60s, the G80 was AMC’s (Associated Motor Cycles, not American Motors) biggest seller, even surpassing Norton, which they also owned. AMC also owned AJS which they turned into a ‘sister-brand’ to the Matchless brand. Very much like Ford and Mercury, or Dodge and Plymouth, AMC built essentially one motorcycle that was changed slightly, mostly in styling, to become two. The Matchless G80 was one, and the AJS Model 18 was the other. The only major mechanical difference between the two bikes was the location of the magneto. Matchless placed it behind the cylinder and AJS positioned theirs in front. Other than that, the only differences were bodywork, paint and trim. In this article, any reference to the G80 should be assumed to also apply to its sister bike, the AJS Model 18.
LEFT: The AJS Model 18 engine mounts the magneto in front of the cylinder.
RIGHT: The Matchless G80 engine mounts its magneto behind the cylinder. Other than that, the two engines are mechanically identical.
The Matchless G80, and the AJS Model 18, typified mainstream motorcycle design, at least in England which followed a set pattern: 500cc undersquare single, air-cooled, OHV (overhead valve), with non-unit construction (engine and transmission were separate components held together by brackets). As such, it was one of the best. However, there was a lot of competition out there at the time (1940s to early 1960s). BSA had it’s legendary Gold Star. Ariel had the Red Hunter, both respectable dirt bikes, as was the Matchless G80. Of course, Matchless wisely made some street versions also, and in that arena they were up against the Royal Enfield Bullet, Norton ES2, any of VelocetteVelocette’s big singles, and even the Vincent CometVincent Comet. All these bikes were surprisingly similar, sharing virtually all the basic featured mentioned above.
The 1948 Matchless G80 was a gorgeous machine with it's chrome tank, painted panels, hand pin-striping, elegant emblem and painted rims. Note the rigid frame in its last year.
Matchless G80 Chassis Design
Early Matchless G80s used a rigid frame (no rear suspension), but in 1949 a new frame arrived with swing arm rear suspension. The first G80s were called G80L to denote that they came with a telescopic front fork, AMC’s own ‘Teledraulic’ front fork. Once the swing arm arrived in 1949, they rechristened it G80S. Velocette was one of the first motorcycle manufacturers to use a rear swing arm suspended on two shock absorbers, and AMC copied them. The first shock absorbers used were called ‘Candlesticks’. These early units weren’t very good at damping, with only 50cc of SAE20 oil inside, and they leaked. They lasted only from 1949 to 1951 when they were replaced by the equally well-named ‘Jampot’ shocks, which in turn were replaced in 1956 by the excellent Girling shocks.
Just looking at the 1948 Matchless G80 engine shows how undersquare they were. That very tall cylinder (long stroke) and it's small diameter at the bottom (small bore) made it a torque-monster. Most British singles of the day were this way.
Matchless G80 Engine Design
The engine started out with a compression ratio of just 5.9:1. Credit that to the poor quality of fuel that was available in the UK just following World War 2. While earliest Matchless G80s used conventional coiled valve springs, they were switched with ‘hairpin’ valve springs in 1949. All alloy cylinder head was added in 1951 and as the petrol improved in England, the compression ratio was increased to 7.3:1 in 1956. The low compression made it easier to kick start, and while they weren’t super fast, they were torquey and got great fuel economy.
The primary chain case was originally fabricated from pressed steel. They were prone to leaking so in 1958 it was replaced by a cast alloy unit. The Burman gearbox, very common at the time, was used on the Matchless G80 initially, but was changed to an AMC gearbox in 1957.
This 1967 Matchless G80 was the 'enduro' version, with high-mounted side exhaust and greater clearance in the fenders. While street legal, it was intended for some off-road work.
Matchless G80 Variants
A long-stroke version of the Matchless G80, known at the G80CS was produced from 1951 through 1955. In 1956, the bore was increased and the stroke shortened. They continued to use the G80CS moniker, citing the ‘C’ as meaning ‘Competition’, and the ’S’ referring to the sprung frame (swing arm suspension). The bore was increased again, to 89mm to create the 600cc G80 Typhoon from 1959 to 1962. Less than 300 were built.
The 1988 Harris-Matchless G80 was a handsome, well-built machine with all the best parts. Unfortunately it was nearly $1000 higher in price than a comparable Yamaha.
Les Harris Matchless G80
To cap off the Matchless G80 story, AMC went belly up in 1966, Manganese Bronze holdings ended up with Norton and Matchless/AJS. Norton went on to fame and fortune (well, maybe not fortune), which lasted until 1975, but that’s another story. Matchless was a name that got bantied around from time to time on various motorcycles. But in 1987, motorcycle legend Les Harris created a new Matchless G80 using a modern Rotax OHC engine, using mostly Italian cycle parts like Paioli suspension, a Dellorto carburetor, a Lafranconi muffler and Brembo brakes, all on a custom Italian frame. They were amazing bikes, but being mostly hand built in Italy, they were expensive and the project failed due to insufficient sales. However, Harris did it right and he knew how. He’d purchased the licensing rights to the Triumph Bonneville when the Meriden factory closed in 1983, and he produced Bonnevilles in low volumes until 1989 or so. Production ended in 1990.
Matchless G80 Motorcycle Books
 |
"AJS/Matchless Gold Portfolio, 1945-1966" By Brookland Books, Ltd., 172 pages |
More Matchless Motorcycles Pages
Hope you're enjoying my website. Glad you're here, take some time to look around. I'm just getting started though, with lots of great content, pictures and specs on literally hundreds of classic British motorcycles left to go. It is my goal to cover every year of every make, and every model of British bike. You can join me in my quest. If you have a classic Brit bike, take and/or send me some great photos of it along with a description. Email coming soon. More pages coming soon. Please be patient, and hold on to your hat. Thank you for visiting ClassicBritishMotorcycles.net.
Copyright 2024 by ClassicBritishMotorcycles.net. All rights reserved.
