Make: Royal Enfield
Model: Model K
Engine: 1140 cc (85.5 x 99.25 mm bore and stroke) 50° side-valve vee-twin
Tyres: 4.00 x 19 in, wirde edge
Frame: Brazed-lug duplex tubular loop. No rear springing
Front forks: Centre-spring girders
Brakes: Drums, 8 in diameter front and rear
Weight: Not known
Wheelbase: 59 in
Manufacturer: Enfield Cycle Co. Ltd., Hewell Road, Redditch, Worcs

Except for the 1,150 cc Brough-Superior (of which only a few were made, anyway), the 1,140 cc Royal Enfield Model K was the most massive motorcycle available on the British pre-war market. But whereas the rider of today equates size with shattering speed, the big Enfield was not exceptional. Certainly it could be supplied to special order, with solo ratios in its four-speed gearbox, but sidecar gearing was standard, for the Model K's role in life was as a heavy haulier.

This was the machine to which a trader would attach a float to carry ladders, bags of cement, and the tools of a builder's business; it would carry a farmer's beasts to market; with a suitably decorated box chair, it sold ice-cream at the seaside on sunny summer Sundays; and, neglected and unkempt, with a plank tied to a bare sidecar chassis, it was a motorcycle dealer's hack, used to deliver or collect a customer's machine.

The Model K was the only bike in the 1939 Royal Enfield catalogue which still retained a hand gearchange. But who needed the slickness of a footchange on a bike like this, anyway? There had long been a 976 cc vee-twin in the Royal Enfield range, but in September 1936 the model underwent a complete redesign, to emerge as a sophisticated 1,140 cc model with dry-sump lubrication and the oil compartment cast integrally with the crankcase. Indeed, there were no fewer than four oil pumps, all with the oscillating plunger pattern which was a long-familiar Royal Enfield feature.

The oil pump fed the big-end bearings, another the front cylinder; the third pump delivered oil into the timing-gear housing, while the fourth returned surplus oil from the timing gear to the oil tank. Engine and gearbox were housed in a full duplex cradle frame, in which the front down tubes passed either side of the projecting crankcase oil container. An oil-bath primary chaincase was provided, but the clutch ran dry in a separate compartment. The catalogue price was £70, but for £5 extra the machine could have interchangeable wheels.

Normally, the Model K had a hand-operated clutch, but if required it could be supplied with American-style controls including a foot clutch. In October 1938, Motor-Cycling road-tested the machine with a huge touring sidecar attached, and, with the chair occupied by a 14 stone passenger, the outfit clocked a respectable best-one-way speed of 62 mph, with a two-way mean of just over 58 mph. Fuel consumption was a bit disappointing, at 44 mpg on the open road.

Production of the Model K ended officially at the outbreak of war, the factory thereafter turning out thousands of 346 cc Model C and Model CO singles for military service. However, one more Model K was built, some time around 1941 - a rather special version, with a live rear axle and prop-shaft drive to the sidecar wheel of a military-style outfit similar to the Norton Big Four. It was an experiment, built in the hopes of attracting a military contract which, alas, failed to materialize. The Army, it seemed, had decided to abandon cross-country sidecars in favour of the Jeep.

Surprisingly, the sidecar-drive Model K was not scrapped, but with prop-shaft removed it served the factory for many years as a hack, carting spares until well into the 'fifties. It was then sold off, bought by private enthusiasts, and survives to this day rebuilt to its original military condition as a reminder of something that could well have worked, given a touch of encouragement from those in high places.

Out of: 'Classic British Motorcycles Of Over 500cc' by Bob Currie 


© by manuk lee  since 4/16/96