FOR WORLD’S RECORDS
DETAILS OF THE A.J.S. SPECIAL A’,THOUGH for some time it has been common practice in the car world to build special machines for attacks on the land speed record, in the case of motorcycles practically standard machines have been used as a basis for the attempt. Such machines are exemplified by the BroughSuperior used by Herbert Le Vack, and the Zenith used by Capt. 0. M. Baldwin. In each of these cases the
engine has been a standard bigtwin racing J.A.P. suitably tuned-up for the sprint.
The recent annexing of this record for sheer speed by the German B.M.W. has now stimulated the motorcycle industry of this country to consider making a serious attack on this record, instead of leaving it, as in the past, to private enterprise. A machine which has been prepared for this
event, and which has many features of interest, is the big A.J.S. which will be ridden by Capt. Baldwin, who has held the record before and has every intention of regaining it.
Seldom has a specially-designed racing machine had a more auspicious entry into the world. Although it is in every way specially designed for the particular task, and is quite unique among two-wheeled racers, there is absolutely nothing freakish in its construction. This, of course, is due to the remarkably extensive racing experience of the enterprising firm of A. J. Stevens, whose products have for more than a decade been in the very forefront of racing machines, and whose experience of motorcycle construction goes back to the dark days of mechanical propulsion. Mr. Jack Stevens, who is manly responsible for the record machine, in discussing various unorthodox features which were being adopted on some makes some time ago (and which have since passed into oblivion), said, “We prefer to work on lines which we know are sound,” and it is this policy of experiment with experience, and moderation in the adoption of new features, which has been the policy responsible
for Capt. 0. M. Baldwin’s racer.
The majority of the components, although forming a unique whole, have all been thoroughly tested in the hard school of racing on road and track, and the machine is a perfectly normal and remarkably good looking motorcycle.
The frame is a very massive loop job, with a single top tube, and neatly housed in this is the 1,000 c.c. engine. This is a 500 twin with a bore and stroke of 79 mm. and 101 mm. respectively, and although quite different from any previous product of this factory it consists in its essentials of parts which have already broken many records. The cylinders are almost exactly similar to those used on the 500 c.c. racer, and have their inlet ports at the rear in each case. The barrels are turned from the solid steel billet and the bores are hardened. The heads are aluminium with bronze valve seats and guides, this being a revival of the methods used by this firm in. the T.T. some years ago, and therefore by no means untried. The valve gear is identical with the chain driven overhead camshaft type used on their present machines, and the two camshafts are driven by separate chains. Two separ ate Amal carbur
ettors are used. The crankcase is very heavily ribbed externally, especially on the sprocket side. On the timing side an oil pump is situated. The lubricant is forced first to the front camshaft bearings, and a second pump inside the timing case delivers it to the rear cases. The oil is returned to the reservoir from just above the lowest level of the fly-wheels,
with the idea of reducing oil drag to a minimum. The gearbox is a 3-speed Sturrney
Archer, with ratios of 3.2 to 1, 4.3 to 1, and 7.8 to 1. The gear change is by foot, and it is interesting to note that an Aren’s Controls, similar to that now used on aircraft replaces the usual rod system. The plate clutch is very massive as are the chains.
The wheels are specially built, the big hubs being machined from solid steel bar. The bearings are of the non-adjustable ball type. At the time of writing, it is under
stood that Captain Baldwin is about to go to Arpajon, near Paris to make an attack on the record, in company with J. S. Wright and Eddie Meyer, who will also make attempts, the former on his 0.E.C., and the latter on a Brough-Superior.