| R.A. Douglas |
Initially, there was no such thing as a speedway bike, everyone rode whatever they happened to have, more often than not a road bike shorn of all but the essentials which could well have been ridden to a meeting. But it soon became obvious that some machines were much more suitable than others for this type of racing.
High on the list of desirables was the Douglas Twin, which had a low centre of gravity, was easy
to ride, had a good power output which would respond well to tuning, and could be slid with
ease on a loose surface.
Already, some of the leading Australian riders had made quite a name
for themselves, Douglas
mounted, by using what was basically the Les Bailey designed RA model,
the type of machine on which
both Freddie Dixon and TomSheard had scored their 1923 TT wins. It is
difficult to say who was the first to use a Douglas on the dirt with
marked success, though it seems probable that this distinction must be
shared between Charlie
Datson and his brother Jimmy. Certainly Charlie's original engine was
displayed for a while in the
Douglas works. But the first Riders to have tangible links with the
factory were Billy Galloway and Keith
McKay, who were loaned RA models when they arrived in England to ride
in the Historic
High Beech meeting.
Note: The R.A derived its name from the "Research Association" Brakes, an early form
of Disc Brake in which the disk is made of friction material.
In 1909, Les Bailey (Stephen Leslie Bailey), the designer of the R.A Douglas, conducted a cycle
and motorcycle shop in Tamworth, Australia. The only racing track in existence at that time
was the Sydney Showground, where Les was an outstanding rider mounted on an Excelsior.
Early in 1910, the urge to go overseas came over him, and on arrival, Les secured a job at the
Humber Motorcycle works as a tester. He studied engineering and earnt high honours in his
exams, which led him to a position within the design office where he designed and produced the
1911 Twin Humber that was a great success.
He very quickly came under the eye of Billy Douglas who made him a very good offer to switch to
the Douglas Kingswood factory and became a habitue of the Brooklands track. Les returned to
Australia in 1913 taking three Douglas's with him where he won the Victoria 50 mile Road race,
and established a new record covering 62 miles in the hour.
During the War Years, Les was virtually in charge of the whole Douglas works churning out machines for dispatch riders in France. However, owing to an unsatisfactory change in management and the retirement of the senior members of the Douglas family, Les resigned and returned home to Australia in 1924.
| R.A. Specifications |
ENGINE: Vibrationless horizontally-opposed twin-cylinder. Bore 57mm x 68mm Stroke
giving 346cc 2.75 model and 68mm X 68mm, giving 494cc for the 3.5 model.
CRANKCASE: aluminium casting with polished exterior, no crevices to collect dirt, constructed
in two sections of great rigidity, with incast brass bushes to take all threads and bearing housings.
CYLINDERS: fine iron castings with deep fins.
HEADS: detachable with big radiating surfaces. Valves set at 45 degrees with scientifically correct
parts, internally machined throughout. Hemispherical combustion chamber giving perfect gas flow
with the maximum turbulence.
VALVES: overhead with large diameter double valve springs, operated by automatically lubricated rockers,
tubular pushrods and robust tappet gear.
PISTONS: special alloy with two narrow rings at top, solid centre web takes the thrust in
both directions and eliminates piston wall distortion, little end bearingslubricated by pressure
of oil scraped from cylinder wall on the downward stroke of piston.
CONNECTING RODS: of "H" section carefully balanced with double row roller big ends.
CAMSHAFT/CRANKSHAFT: mounted on heavy ball bearings. Special balance weights are arranged to minimise
couple. All materials used throughout are special expensive alloy steels.
MAGNETO: E.L.C or other first class British make, carried above engine under the tank, protected
efficiently but quickly removable without disturbing the timing of the magneto or removing the cover of the timing chest.
CARBURETTOR: Twin Douglas, Amac or Binks, according to supplies, with aluminium air box, right hand
twist grip control and extra air lever.
LUBRICATION: Oil is carried in aluminium trough below the engine from whence a handlebar controlled pump feeds
oil via a tank indicator to the front cylinder, lubricating by splash the rear cylinder and
the engine beartings.
TRANSMISSION: Sweet running all-chain drive amply protected (Renolds or other first class make).
CLUTCH: Douglas patent single plate incorporated in the flywheel. Of smooth action and light
operationit will stand a deal of abuse and is simple to adjust in a few seconds.
BRAKES: Powerful wedge type. Special alloy shoes operating on friction material rims. Quick
finger adjustment for wear. Correct radial movement is afforded to both back and front shoes by semi-parallel link motion.
FRAME: Douglas design Duplex cradle construction of highest grade weldless steel tubing.
Extremely low engine position, all lugs are machined from solid steel components. Lowest possible
riding position.
FRONT FORKS: Built to suit the cradle frame with central spring suspension and one-piece connecting links. Hollow
spindles with wick feed delivering oil to all bearings automatically.
TANK: Sturdily built supported on brackets brazed solid with the frame, provided with petrol feed wells
eliminating air locks and an extra large spring-open filler cap. Rubber knee grips anchored
to the sides of the tank infinitely adjustable.