THE name "Roc" has been associated with motor cycle gears from the earliest days, so that it was with some interest that we examined the latest type of countershaft two-speed gear manufactured by Messrs. A. W. Wall, of Hay Mills, Birmingham.
The gear is of the constant mesh type, employing a single pair of sliding dogs to effect the change. A particular feature of these dogs is that every alternate projection is somewhat higher than its neighbour. This is arranged so as to give an easy and positive change. and allows a full quarter revolution for engagement. A short road trial of the device fitted to a small two-stroke showed that the gears are particularly quiet, both on the high and low ratios, while the change can be made with the greatest ease. The construction of the box is very solid, and all parts are strong enough to withstand considerable overload The main shaft runs on ball bearings and the layshaft on plain. At present the gear is manufactured for use on lightweights only.
The Motor Cycle, July 30th, 1914.