Model 18 1945-66 498cc ohv single, 400lb, 55mpg, 80mph

This was the 500cc version of the models 16 & G3. It had slightly better handling & was more pleasant to ride.

Model 20 1948-61 498cc ohv twin, 410lb, 60mpg, 90mph

Introduced when twins were vogue. Late ones have alternator electrics & better frames. The early have odd handling characteristics & very poor brakes.

Model 30 1956-58 593cc ohv twin, 410lb, 60mpg, 90mph

This 600cc twin is difficult to come by & is slightly better than the 500cc. There is also a sports CS version.

Model 31 1959-66 646cc ohv twin, 430lb, 55mpg, 100mph

Enlarged 600cc engine which improved in build after 1960 with new cylinder head & lubrication system. They acquired Norton forks & wheels in 1963 along with 12v electrics. The sports CS & CSR versions are more sought after but this also has a more fragile engine.

Model 33 1964-69 749cc ohv twin, 420lb, 45mpg, 110mph

AMC put the Norton Atlas engine into the Matchless cycle parts. It was very powerful, but they did vibrate a lot & the engine is fragile.