Frame

Numbered 36443 to 42995 (approx). Bolt on seat stays with drawback type chainstays for rear wheel adjustment.

Wheels

WM1x21 (f), WM1x21 (r).interchangeable with black painted rims. Black spokes with NPB nipples. Rear with bolt on sprocket.

Mudguards

Inverted 5” wide U section, both unvalanced. Rear, with detachable tail section.

Tanks

Petrol/oil tank finished in black & gold. Twin Westwood type fillers with front fitted petrol balance pipe. Single bolt damper arm fixing. Brass lever petrol tap.

Engine

Numbered 1 to 5100 (approx) - 4 valve 340cc with cast iron open valve cylinder head, parallel inlet and exhaust. Rockers supported in large nuts mounted on plates bolted to the cylinder head. 18mm side plug. Forward mounted type F 6V ML Maglita or round ML magneto. Round based cylinder barrel and webbed (6) drive side crankcase. Oil feed to rear of cylinder. Timing side crankcase with ‘Rudge Whitworth’ cast in. (note that early crankcases did not have the ‘Rudge Whitworth’ cast in). Cast alloy oblong rocker cover with ‘R-W’ cast in.

Brakes

6 3/4” front and rear, coupled with steel shoes.

Electrics (optional)

Miller 7” headlamp with No 74E 6-0-6 'Lighthouse' ammeter # and 34E rear lamp (where fitted).

Transmission

4 speed gearbox with hand change on RHS of tank. Steel primary cover (not oil bath). ‘Rudge Whitworth’ cast into gearbox quadrant cover.

Carburetter

Amal type 6/109 with 2 lever control (twist grip optional)

Exhaust system

Twin 1 1/2” low-level downpipes into Rudge ‘can’ type silencers and 6” fishtails.

Standard Fittings

Rear carrier (extra at no charge), 1” handlebars with folded type inverted levers and steering damper. Single toolbox fitted to offside of machine opposite the battery. Spanner adjusted fork shock absorber. Pressed steel centre stand. Open ended ‘D’ section forks.

Extras

Chromium plated tank with black or maroon panels. Nickel plated tank with black or maroon top and side panels. Maroon panelled tank and mudguards. Bonniksen trip/non trip internal drive speedometer. Time speed meter. WM2x21” or WM3x19” wheels.

©  Colin Chapple