Douglas Motorcycles

Today in Motorcycle History

Douglas Motorcycles 1923

733 c.c. o.h.v. Douglas for 1923

Now standardised as a sports solo mount, the 733 c.c. o.h.v. Douglas will appeal to the big twin enthusiast despite its moderate engine size.

Douglas Lightweight for 1923

Many of the features on the larger sports models are incorporated on the new chain-driven lightweight.


348 c.c. Model now offered with Alternative Transmissions.

Wide Scope of 1923 Programme. Many Refinements.

DOUGLAS is a name that needs little introduction. It is doubly famous as the pioneer of the flat twin and the 350 c.c. lightweight, and in another form, as the only 500 c.c. motor cycle to attain 100 m.p.h.

Changes for 1923 consist chiefly of detail improvements, but three variations of existing mode's, virtually earning the term new models, deserve attention. These are the chain-driven 248 c.c. lightweight, the chain-driven 595 c.c. machine, and a model of the 733 c.c. machine specially designed for solo use.

Many of the features on the sports models have been incorporated in the new lightweight, including improved contracting wedge type brakes and knockout spindles on both wheels, and a transmission shock absorber in the flywheel. Considerably improved mudguards have also been evolved, and the silencer is doubly larger than hitherto.

Engine and Saddle Refinements.

All the engines of the 348 c.c. machines (two-speed belt, three speed belt, and three-speed chain) have received attention, "H " section connecting rods of special material being now fitted. Also a new saddle suspension has been designed; the front is supported by a single leaf spring attached direct to the top tube, and the rear coils springs hang directly from the rear stays cross bolt, thus giving an appreciably lower riding position.

In general the above-mentioned changes apply to the 733 c.c. machine in its solo form, and, in part, to the large sidecar outfit. Aluminium footboards or adjustable foot-rests are optional on the solo edition, which, although some way from 1,000 c.c. should prove a very capable upholder of the reviving British big twin class.

As a proved example of high efficiency design the o.h.v. 494 c.c. engine has not been greatly altered. Careful thought, however, has been given to the provision of the most suitable steels for valves, rockers, etc. Wick lubricated rockers, double roller big-end bearings, double row ball main shaft bearings, and its other distinctive features are, of course, retained.

The rear axle unit, including the rear wheel shock absorber (there is another on the engine shaft), has been re-designed in a considerably more robust 'form; and greater leverage and consequently a lighter handle-bar operation is provided for the clutch. The handle-bar fixing has also been "cleaned up," so as to give a lower and more comfortable position for speed work. The new type of saddle suspension is again employed, and the mudguards are exceptionally efficient for a sports model.

For fast sidecar work the gear box has been strengthened up, particularly the pinions, which are now of the stub tooth type in 5 per cent, nickel steel. Separate legshields replace the 1922 type of single auxiliary guard, and a pillion seat has been incorporated with the lid of the combined rear carrier and tool box. The sidecar body carries a neat luggage grid, and is fitted with the special Douglas sliding dash and a Triplex windscreen, with a curved face if desired. Various slight improvements have combined to make the sidecar chassis more than strong enough for this very fast machine.

Quite a different type of vehicle is the 595 c.c. Douglas, which is available, solo or sidecar, with final chain or belt.

The belt-driven machine remains substantially the same as before, although the cylinder heads, mudguards, and saddle have all been improved. Chain-driven, it follows the lines of the sports models in transmission, wheels and brakes. Touring or flat bars are supplied.

Absolutely complete equipment is supplied with every Douglas model.
The Motor Cycle November 16th, 1922. p698


The 1922 Olympia Show.

DOUGLAS. (61.)

Touring and Racing Flat Twins.

2¾ H.P. Model.

60.5x60 mm. (348 c.c); flat twin cyl. four-stroke; side-by-side valves; drip feed lubrication; Amac carb.; gear-driven mag.; 2-5p. gear; no clutch or kick-starter; chain and belt drive; 26x 2¼in. tyres. Price £50.

Douglas Motors, Ltd., Kingswood, Bristol.

For many years the Douglas motor cycle has held a position on the market entirely of its own, and the recent successes of the larger machines have brought the make prominently before the public in the last few weeks. The 348 c.c. machine is practically identical, as far as its main lines are concerned, with the motor cycle with which the Douglas firm made its name, but it is available, of course, now both with the belt and with chain drive, clutch and kick starter, and three-speed gear.

3½ H.P. Model.

68x68 mm. (494 c.c); flat twin cyl. four-stroke; overhead valves; mechanical lubrication; Amac carb.; gear-driven mag.; 3-speed gear; clutch and kick-starter; chain drive; 650x65 mm. tyres. Price £95.

In addition there is the 494 c.c. model, with which so much has been done at Brooklands and which was the first machine of the 500 c.c. class officially to exceed 100 m.p.h. This engine is, broadly speaking, on the same lines as the 348 c.c. model, but has overhead valves, and the machine shown on the stand is of the Tourist Trophy type. There is also the 733 c.c. model, intended especially for sidecar work, which is very much on the same lines as the 494 c.c, save that the engine has a bore and stroke of 83x68 mm. (733 c.c).

Finally the 595 c.c. machine, also chiefly for sidecar work, is exhibited, and has mechanical lubrication. This engine has been but little altered of recent years, and is almost of the same design as the smallest machine, save that the frame is on the lines of the 494 c.c. type. The bore is 74.5 mm. and the stroke 68 mm. The price of the 595 c.c. model is £85 solo, £110 with sidecar.

Olympia Show 1922
The Motor Cycle, November 30th, 1922. Page 855

If you have a query or information about Douglas motorcycles please contact us