(continued from Editors and the Vauxhall Motorcycle)
Air-cooled, of “square” cylinder dimensions, with a wet sump, the overhead valve gear was fully enclosed. Wick lubrication was provided for the rockers on the vertical overhead valves; bottom-end oiling was by dippers on the ends of H-section connecting rods. The clutch was constructed of alternate steel and bronze plates, a 3-speed gearbox was in unit with the engine, and a shaft turned a worm and pinion final drive. Bill Snelling of Classic Motorcycling Review rode the surviving example from the Isle of Man museum and found it heavy, with large mounting lugs on the side of the frame suggesting perhaps Vauxhall had the sidecar market in mind. He thought it “a fabulous machine, way ahead of its time.” It had managed a lap of the TT course in top gear, though the engine was, “Very softly tuned.”
Halford’s shaft drive motorcycle was contemporary with BMWs at the Paris Salon in 1923, but while BMW’s Bayern Kleinmotor transverse twin became a motorcycling classic the Vauxhall disappeared into history. Two prototypes of Halford’s design were made, with components for a further four frames and 10 engines. In Britain where motorbikes were still largely working class transport, it was too expensive. Girder forks, single cylinders, and belt or chain drive continued. Sports motorcycles like this Vauxhall were almost unknown and the project was dropped.
Halford went on to race cars at Brooklands, his AM Halford Special retiring from the 1926 British Grand Prix with a broken drive shaft, after what Motor Sport described as, “a very good chance of winning.” Halford had a distinguished career in aero engineering with the Royal Aircraft Establishment at Farnborough, later with Arroll-Johnston. He was the “H” in the BHP aero-engine consortium with Beardmore and Pullinger, created the Cirrus engine for de Havilland in 1924 and worked on the flat-H liquid-cooled Napier Sabre, which inspired the late Tony Rudd at BRM. Halford’s work with Sir Frank Whittle, the jet engine pioneer, led to the Halford HD-1 later renamed de Havilland Goblin, used in the Vampire fighter, and famously handed over in 1943 for the first American jet, the Lockheed Shooting Star.[Image]
(picture courtesy http://www.wing-web.co.uk)
VAUXHALL single-seat motorcycle, weight 193kg (425lb).
ENGINE 4-cylinders, in-line, mid; 67mm x 67mm; 945cc; 22.4kW (30bhp) @ 3,500 rpm; 23.7kW(31.7bhp)/l.
ENGINE STRUCTURE pushrod overhead valves; side camshaft; cast iron integral cylinder heads and barrels; aluminium crankcase; 3-bearing 2-piece crankshaft; single carburettor; magneto ignition; 6-volt electrics; air-cooled.
TRANSMISSION rear wheel drive; 6in multi-plate clutch; 3-speed gearbox; shaft drive; worm final drive; ratio 3.5:1.
CHASSIS DETAILS duplex cradle frame; coil-sprung twin forks front suspension; no rear suspension; no dampers; 17.8cm (7in) drum brakes; 20.5l (4½ gal) fuel tank; 700x80 tyres.
DIMENSIONS wheelbase 147cm (58in); length 229cm (90in); height 99cm (39in).
PERFORMANCE maximum speed 132kph (82mph); 38.5kph (24 mph) @ 1000rpm; fuel consumption 4l/100km (70mpg) @ 80kph (50mph).
PRODUCTION 2, see text