28. AJS 37A-T 250cc Trials Bike
The AJS 37A-T trials bike, was put into production in 1969, whilst this has much in common with the Y4 in general design, there are several differences.
In the first place, torque is of far more importance than a high power output for mud-plugging, and the 246 cc Mark 37A engine is notable for its ability to slog at low speeds in the stickiest of conditions. It produces 12.4 bhp at 5,000 rpm with a maximum torque 16 lb/ft at 3,200 rpm, on a 7.9 – 1 compression ratio. The carburettor is a S25 Villiers unit, with renewable paper element. The four-speed gearbox is manufactured by AJS and has ratios of 3.6, 2.4, 1.56 and 1.00 to 1.
AJS 37AT Trials / 1969
A high-level exhaust system is used, the pipe being carried over the top of the engine; the silencer is tucked neatly below the rider’s seat and with adequate protection against burning the rider’s legs.
Cotton Motorcycles Ltd built the frames, based on the Y4, for AJS from cold drawn steel tubing. It is sif-bronze-welded, with a tapered top-tube for maximum rigidity, and has a single down tube. The forks are Metal Profile, designed to accept the continuous hammering which machines have to take in the devilish sections, which are a feature of modern trials. Girling oil-damped units take care of the rear suspension and the swinging arms are constructed from 1¾ inch tubing, pivoted on ‘lubricated-for-life’ bearings.