NOVEMBER 30th, 1922. Page 751
The Olympia Show.
Except in the engine the T.B. three-wheeler follows car practice; it embodies a three-speed gear box and reverse, final shaft drive, semi-elliptic springing in front, and a form of cantilever suspension at the rear.
The standard model employs an air-cooled J.A.P. engine, while a water-cooled V-twin of the same make is fitted to the de luxe model. Finally, there is an aluminium-bodied sporting machine using the super-sports air-cooled J.A.P. engine.
Full equipment of horn, screen, hood, lamps, tools, and jack is supplied in every case, a spare wheel and electric lighting being included on the de luxe and sporting types.
Dot motor cycles have been on the market now for twenty years, which fact alone should carry considerable weight with the visitor to Olympia.
For next year all the machines have been thoroughly modernised, and, following the fashion of the day, are offered in sporting and touring guises. A 976 c.c. super-sports J.A.P.-engined 80 m.p.h. model deserves premier attention, but the 346 c.c. J.A.P.-engined sporting solo machine is also a good example of its class. Three-speed Sturmey-Archer and Albion gear boxes respectively are used, final drive being by chain. Adjustable handle-bars are a minor but useful refinement. 350 c.c. o.h.v. Blackburne, 250 c.c. J.A.P., or 350 c.c. Bradshaw engines may be fitted to the lightweight.
Considering that the speed model flat twin Brough is only 496 c.c, it is very remarkable that it should be supplied with a guarantee to exceed 80 m.p.h. This requires a specially-tuned engine, but the standard speed model is capable of 70 m.p.h. Overhead valves are employed, and aluminium alloy pistons and roller bearings for the crankshaft and the big ends also find a place on this model.
A touring model with a side-valve engine of the same size is also supplied for solo or sidecar use; a side-valve 682 c.c. dual-purpose machine completes the exhibit.
Extensions have taken place to the famous range of Douglas flat twins, mainly in the form of additional models of existing types. For example, the familiar 348 c.c. Douglas may now be obtained with chain transmission and external contracting brakes on both wheels; the 595 c.c. model (which was virtually re-designed last year) is also offered with alternative transmissions; and the o.h.v. 733 c.c. machine is standardised as a sports solo as well as sidecar mount.
Perhaps least change of all has been made to the 494 c.c. o.h.v. Douglas, but even here considerable improvement has been effected in the transmission.
The Motor Cycle, November 1922
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