Numbered 18457 to 24375 (approx). Bolt on seat stays with drawback type chainstays for rear wheel adjustment.
WM1x21 (f), WM1x21 (r). interchangeable with black enamelled rims. Black spokes with NPB nipples. Rear with separate rear sprocket carrier assembly. (dogged drive).
5” D section, unvalanced, front and rear. Rear with detachable tail section.
Petrol tank black with double gold lined panels fitted between frame rails (flat tank). Single 2" external screw type filler. Brass lever petrol tap. Oil tank mounted on rear frame down tube across the frame with screw filler to offside.
Numbered 39500 to 46000 (approx) - Tuned (higher compression) 4 valve 499cc with cast iron open valve cylinder head, parallel inlet valves and parallel exhaust. Forward facing parallel exhaust ports.18mm side plug. Rockers supported on plates bolted to the cylinder head. Forward mounted ML Maglita or round ML magneto. Square based cylinder barrel and plain drive side crankcase. Total loss oiling with Best & Lloyd pump mounted on timing cover.
Dummy belt rim front and rear, coupled to RH pedal.
6V or 4V ML.
4 speed semi close ratio gearbox with hand change on RHS of tank. Gearbox with external kickstarter stop. Steel primary chain cover and ‘angle iron’ type chainguard.
Amac 15TT 25# with Amac 2 lever control
Twin 1 1/2” nickel plated low level downpipes into 'Rudge Four' polished aluminium expansion chambers with detachable nickel plated tail pipes.
Dropped 7/8” non adjustable handlebars with folded type inverted levers. Rear stand. Leather fronted toolbox mounted on rear carrier on nearside of machine. Steering damper operated by wing nut through the steering head. Battery carrier (where fitted) mounted on offside of machine to the rear of the gearbox. Lycett Aero saddle. Closed ended ‘D’ section forks. Andre fork shock absorber.
Rear brake lock for use when a sidecar is fitted. Rear carrier.