Frame

Numbered 36443 to 42995 (approx) in Rudge sequence. Special speedway with curved front and rear downtubes. Un-strutted. Special kneehook lug. Frame numbered in Rudge sequence. Steering head fork stop machined off. Bolt on seat stays with drawback type chainstays for rear wheel chain adjustment.

Wheels

Front with special speedway hub with no drive dogs. Rear, dog drive type with large flange on drive side. 28 x 2 1/4”/2.3/8” beaded edge rims, chrome plated. Black spokes with NPB nipples.

Mudguards

Short black enamelled back and front ‘D’ section with cinder guard in front of engine.

Tanks

Red enamelled parallel sided petrol tank with front recesses for fork clearance fitted between the frame tubes. Single Westwood type filler. Oil tank, red enamelled, larger than 1928/9 with single Westwood type filler.

Engine

Numbered 1 to 5100 (approx). Total loss version of the 1930 Ulster - 4 valve 499cc with iron open valve parallel inlet & parallel exhaust cylinder head. 18mm central plug. Rockers carried on cast pillars. Forward mounted ML magneto running at half engine speed. Round based cylinder barrel and webbed (6) drive side crankcase. Timing side crankcase with ‘Rudge Whitworth’ cast in. (note that early crankcases did not have the ‘Rudge Whitworth’ cast in).Timing cover, 1928 pattern with vertical adjustable metering ‘pump’. Oil feed to rear of cylinder. Cast alloy ‘oblong’ rocker box with ‘R-W’ cast in.

Forks

Webb speedway pattern.

Transmission

Gearbox based countershaft with clutch or direct drive.

Carburetter

Amal type 29/105 with twin float chambers and fast action twist grip.

Exhaust system

Two 1 1.5” pipes with the offside carried low beneath the timing cover and the nearside swept up to run above the top of the chains.

Standard Fittings

Adjustable 1” handlebars, part chrome/celluloid with modified Rudge steering damper. Riveted angle & strip steel type centre stand.

Extras

Wired on type rims. Rudge Whitworth speedway countershaft. Magneto cut out.

©  Colin Chapple