Frame

Numbered 55701 to 58075 (approx). Integral seat stays with cam type chainstays for rear wheel adjustment.

Wheels

WM2x19 (f), WM2x19 (r). Rear, interchangeable with chrome rims. Black spokes with NPB nipples. Bolt on rear sprocket.

Mudguards

Inverted U section, both valanced, front with bottom splash guard. Rear, two piece with detachable main section.

Tanks

‘Aero’ pattern petrol tank painted black with lined panels with Enots reserve tap. Single central CEE-ESS type filler with front fitted petrol balance pipe. Two bolt damper arm fixing.

Engine

Numbered S2300 to S3100 (approx) - 4 valve 495cc with cast iron open valve cylinder head, parallel inlet valves and parallel exhaust.18mm side plug. BTH KD1 D4 magneto and DM3G dynamo. Oil feed to rear of cylinder. Cast alloy rocker cover with cast 'R' motif. Cast alloy rocker cover on LHS with cast 'R' motif.

Brakes

8” front and rear, coupled with aluminium shoes.

Electrics

Miller 8” headlamp with No 832 8-0-8 'Lighthouse' ammeter and 29E rear lamp. Lucas HF1140 (chrome tone disc nut & polished tone disc) electric horn mounted on special frame lug on rear frame tube.

Transmission

4 speed gearbox with hand change on RHS of tank. Aluminium oil bath chaincase with ‘R’ on dome and separate filler on shock absorber dome.

Carburetter

Amal type 76/113 with Amal straight pull twist grip control. Original settings: main jet 150, slide 6/4, needle jet 106, needle position 2. Chrome plated copper fuel pipe.

Exhaust system

Twin 1 3/4” low-level downpipes into barrel silencers and tail pipes with fishtails.

Standard Fittings

80MPH speedometer and ‘Revulator’. Mechanism shield, battery cover, licence holder, cast central stand with lifting handle, stop light, rear carrier, 1” handlebars. Two toolboxes fitted to either side of machine. Steering damper and handwheel operated fork shock absorber. Round tubed forks. THAPEX tyre inflator. RH chainstay valence. Cover to front engine plates.

Extras

Upswept exhaust pipes, pillion footrests, Rudge quickly detachable and interchangeable wheel on Watsonian or Swallow sidecar. Leg shields.

©  Colin Chapple