Taking It Up To The Heavies
Some historians could argue the G.W.K. does not belong on the Unique Cars and Parts list of great British sports cars of the pre-war era, but the performance of those old friction-driven light cars in reliability trials fully merits a short description of them. In addition, few people know that the G.W.K. caused a sensation at Brooklands in 1912 by winning a race against large-engined racing cars. The "heavies" took a dim view of this, and were mighty pleased when the little car was disqualified on the grounds that it was a cyclecar. G.W.K.s also did quite a spot of record-breaking at Brooklands.
The earliest G.W.K.s had a twin-cylinder engine, mounted at the rear, but post-war (1914 - 1918) cars were made with a four- cylinder 1368-c.c. (66 x 100-mm.) power unit, developing some 22 b.h.p., fitted in the normal position. Chassis construction included the use of tubular cross-members, whilst quarter-elliptic springs were adopted fore and aft.Quite the most interesting feature of the G.W.K. was its transmission. At the end of the prop, shaft there was a friction disc, which engaged with a similar disc on the rear axle, in such a way that it could slide across it.
Any gear from top to bottom could be obtained. Reverse was obtained by sliding the movable disc on the axle across the centre of the prop, shaft disc. Power was transmitted via the friction discs to reduction gears in the rear wheel hubs, which were enclosed in oil-tight cases. In order that the transmission should be as stiff as possible, and that there could be no derangement, the assembly was carried in a separate sub-frame.
The G.W.K. transmission was so simple and yet so effective that it had many imitators. However, the crown wheel and pinion back axle was developed to such an extent that it rapidly superseded all other types of transmission, except on the simple type of cyclecar. It is safe to say that the G.W.K. was the only friction-driven car to be sold in this country in quantity. It had many adherents, and with the possibility of constant-speed turbine engines being developed for road machines, this type of drive may quite well be revived in a modified form. With turbines, acceleration and deceleration will require to be accomplished by variations of the gear ratios, and an infinitely variable gear, through the medium of friction-driven road wheels, might be a possible solution. |
