Frame

Numbered 53961 to 55700 (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 with detachable main section.

Tanks

Petrol tank chrome plated with lined black panels. Single central CEE-ESS type filler with front fitted petrol balance pipe. Two bolt damper arm fixing. Enots non reserve petrol tap.

Engine

Numbered S1151 to S2300 (approx) - 4 valve 499cc with cast iron open valve cylinder head, parallel inlet valves and parallel exhaust. Rockers carried on cast pillars. Cast alloy rocker cover and nearside rocker pillar cover, both with ‘R’ motif. 18mm side plug. BTH KC1 D4 magneto and DM3G Miller dynamo.

Brakes

8” front and rear, coupled with aluminium shoes.

Electrics

Miller 7” headlamp with No 832 8-0-8 'Lighthouse' ammeter and 29E rear lamp. Lucas ‘Altette’ electric horn.

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 Rudge ‘can’ type silencers and 6” fishtails.

Standard Fittings

80MPH speedometer and Smiths C55 8 day clock. Mechanism shield, battery cover, licence holder, pressed steel central stand with lifting handle, stop light, rear carrier, 1” handlebars. Single toolbox fitted to offside of machine. Steering damper and handwheel operated fork shock absorber. Open ended ‘D’ section forks.

Extras

Upswept competition exhaust pipes, pillion footrests, Rudge quickly detachable and interchangeable wheel on Watsonian or Swallow sidecar, Leg shields and footchange. All black finish to petrol tank.

©  Colin Chapple