1961 Matchless G12
650 Twin
1961 MATCHLESS G12 BACKGROUND
Just prior to World War II, Triumph rocked the world with their seminal 500 Speed Twin, but the world had to wait for the war to end before the rest of the industry would have a chance to catch up. At war’s end, BSA was first to respond with their own 500cc vertical twin, the 1946 A7. Norton was next, followed by Matchlessfollowed in 1949, Norton with the Model 7, and Matchless with their G9. Of course, every Matchless came with a matching AJS back then (and they called them “Matchless”), in this case the AJS Model 20. Triumph being the first one to the party, they were also the first to start upping the ante in the horsepower-wars. In 1950, they bored and stroked out their own 500 to make the world’s first Triumph 650, the 6T Thunderbird, and most of the rest of the industry followed suit the best they could. Matchless and AJS countered in kind, bumping their 500’s displacement up to 650cc in 1958, along with new names, the Matchless G12 and the AJS Model 31. These were followed in turn by a larger version still, the 750cc Matchless G15 and AJS Model 33 in 1963.
1961 Matchless G12 SPECIFICATIONS
Model Designations, Matchless/AJS Engine type Displacement Bore & Stroke Compression ratio Lubrication Oil capacity Fuel system Ignition System Power output Battery Primary drive Clutch Gearbox Final drive Suspension, front Suspension, rear Brakes, front Brakes, rear Frame type Tire, front Tire, rear Dry weight Fuel capacity Fuel economy Top speed |
G12 / Model 31 Air-cooled OHV vertical twin 646cc / 39.4 ci 72mm X 79.3mm 7.5:1 Dry sump 2.5 L / 5.3 US pints 1 – Amal 389 1-1/8″ Lucas distributor & points 35 hp @ 6,500 rpm Lucas 6V 12aH 1/2″ X 5/16″ single chain Multi-plate, wet 4-speed, right-foot shift 5/8″ X 3/8″ chain, 96 links AMC Teledraulic forks Swing arm w/2 shocks 7 -n SLS drum 7-in SLS drum Double cradle 3.25″ X 19″ Dunlop 3.50″ X 19″ Dunlop 396 lbs / 180 kg 4.5 US gal / 17 L 55 mpg / 23.4 km/L 95 mph |