MATCHLESS

500 G45 - 1953

Clubman's racer

The Matchless G45 was an unexpected addition to the Plumstead South London company's range at the 1952 London Motorcycle Show. The new clubman racer was an innovation of the machine with which Derek Farrant had won the 1952 Senior Manx Grand Prix. It marked the company's first venture into road racing since 1914!

Birth of the Jampot

The roots of the G45 went back to the introduction of the new G9 500cc vertical twin in 1948. A unique feature of the bike was its three-bearing crankshaft, while the unique shape of the Matchless-made oil-damped rear-suspension units earned them the enduring nickname of "Jampots." The G9 was initially an export-only bike, but within two years was also available on the British market.

Single-Piece Crank

The touring G9 engine was used as the basis of the new model, fitted with a magnificently finned light-alloy cylinder head and a single-piece steel crankshaft. The single-loop frame of the G9 was replaced by the duplex frame of the 7R racer made by Matchless' sister marque, AJS. The G45 works racer had first appeared in the Senior Clubman class of the 1951 TT; as a production machine it was ridden by many well-known riders, perhaps most successfully by Peter Murphy. In its ultimate, 1957, form, the G45 developed 52 hp at 7400 rpm. It was replaced by the new GSO overhead camshaft single, a 500cc derivative of the 350cc AJS 7R.

SPECIFICATIONS

Engine: 498cc (66x72 mm) air-cooled single-cylinder; dry-sump lubrication

Power Rating: 48 hp @ 7200 rpm

Valves: overhead

Fuel System: carburetor

Transmission: 4-speed; chain final drive

Suspension: telescopic forks (front); swinging fork with twin "Jampot" dampers (rear)

Brakes: conical 8.25 inch drum (front & rear)

Wheels: 19 inch (front & rear)

Weight: 320 lb

Maximum Speed: approx. 120 mph

The G45 production racer was a determined effort by Matchless to overthrow the domination of its single-cylinder British rivals.