A Brief History of the Marque
Financed by the acclaimed author Arthur Conan Doyle, Roc motorcycles were produced in Guildford, Surrey, and later in Birmingham to the design of A.W. Wall. The machines used both Precision and Roc engines of 2 to 6 hp, mostly V twins. Wall's designs included three-wheelers and bicycle engines. Production ceased soon after the onset of the Great War.
The ROC was built at the Rex factory in Birmingham (See Rex and ROC)
1904 The Roc had a 3hp engine, free-engine clutch and magneto ignition.
1905 The engine was fitted with an outside flywheel on each side. Although it did not race, a vertical twin-cylinder engine was tried out at the Isle of Man Auto Cycle Cup event by T. H. Tessier.
1905 Henry Percival Rose, 10 Pewley Hill, Guildford, Surrey registered a number of these machines so my have been connected with the company
1906 The machine was listed as having a 792cc engine with automatic inlet and mounted in a spring frame.
1906 September. Listed as an entrant in the Birdlip Hill Climb as '5 h p. Roc (A. W. Wall, Ltd.)'
1908 The new model for that year was the 4hp Royal Military, with a long wheelbase, live rear-axle with clutch and two-speed gear, all in the rear hub. The Roc hub was offered to other makes as a conversion and was well received. The Royal Military was sold as far afield as Australia, by Lewis Motors of Adelaide.
1909 A new front-fork using C-springs appeared and engines were a 4hp single and a 5-6hp twin. The range was extended and the Wall Auto-Wheel first appeared. Roc added a Tourist model with a 515cc four-cylinder engine and pressed-steel frame. A model was also listed with the 4hp single engine.
1910 The firm made its move to Aston Road, in Birmingham.
1911 Two models were advertised under the A. W. Wall name. The first was a single with a two-stroke engine, shaft drive, worm gear, two-speeds, pressed-steel frame, C-spring front suspension and a well-sprung bucket seat. The other was a tricycle with twin rear wheels and body-work that carried the rider and also enclosed all the mechanical parts. Its engine had a rotary inlet-valve, with single or twin-cylinder four-strokes as options.
1912 The model was a 5hp tricycle fitted with a Roc two-speed gear.
1914 Precision engines of 2.75hp and 4.25hp were fitted, the larger of which drove a four-speed gearbox. They also listed a 6hp model fitted with a three-speed gearbox with chain drive.
A. W. Wall, Ltd., Birmingham. Stand No. 81.
A good exhibit of the "Roc" motor bicycles is on view here, some with single cylinders and others with twin engines. A sample of each is shown fitted with the castor wheel side car, for which class of work the Roc 2-speed gear and clutch are particularly adapted. A novelty for this year consists of a spring fork. The main fork is connected to the auxiliary fork by C springs. The two forks are hinged together above the wheel, and there is also a telescopic action giving the wheel very free motion without side shake.
Very few alterations will be made to the Roc machines for 1909. The duplex frame and tank will be retained. The engines will be 4 h.p., 83 by 90 mm. and 5-6 h.p., twin-cylinder, 75 by 80 mm., with ball bearings to the big end of main shaft and one shaft of the timing gear, viz., the one that drives the magneto.
See also A.W. Wall History
Sources: Cycle and Motor Trades Review, 1908 (courtesy Graces Guide), The Motor Cycle, November 1908, earlymotor.com