Calthorpe Motorcycles

Today in Motorcycle History

Calthorpe Motorcycles 1914-1915


Two 1915 Model Calthorpe Machines. The new two-stroke. The 2½ h.p. J.A.P. engined mount


SEVERAL modifications have been made in the little Calthorpe Junior, but the most striking feature is the adoption of the latest type of Precision Junior engine. This engine has been slightly increased in capacity, and, though the main features of combined engine and gear box and cam and gear-shaft in one are still maintained, the cylinder and the valve action are altogether different. The more orthodox type of side-by-side valves, operated by vertical adjustable tappets, have replaced the horizontal valves placed in the head and opened by rocking beams. In spite of this, the fact that the valves lie behind the cylinder instead of at the side forms an interesting feature and renders the inlet and exhaust pipes simple, and in the case of the Calthorpe these are very neatly carried out. The outside flywheel is still retained and the magneto is placed behind the cylinder. Neat footboards are employed and the change-speed gear is still foot-operated as before. The mudguarding is efficient and the Calthorpe Co. has succeeded in turning out a practical businesslike little mount at a reasonable figure.

The stroke remains 60 mm. as before, but the bore has been increased to 65 mm., which brings the capacity up to 199 c.c.

We were glad to note the adoption of girder type Druid forks and 2in. studded tyres. These two points were the subject of criticism in The Motor Cycle some few weeks ago. The price remains at twenty- five guineas.

New Two-stroke Model.

An entirely new departure is the marketing of a two-stroke mount of 2½ h.p. complete with counter-shaft two-speed gear and chain-cum-belt drive. The specification includes Druid girder forks. XL'all pan saddle, a new tank, and sight feed lubrication.

The lubricating oil on this machine is kept entirely separate from the petrol. The Calthorpe Co. are of the opinion that the "petroil" mixture will be discontinued generally, as from their tests it is found that much greater efficiency is shown by keeping the two constituents apart. The two-stroke Calthorpe with fixed gear costs but £25 4s. and the two-speed model £28 10s.

The 2½ h.p. Calthorpe-Jap.

Still another new mount for 1915 is a lightweight fitted with a 2½ h.p. J.A.P. engine. This mount follows very much the lines of the two already described, except that it has an Enfield two-speed gear. Chain-cum-belt drive is retained, and other points of the specification are 2in. beaded-edge studded tyres, Druid girder forks, and XL'all pan seat. This machine also has the new design tank and sight feed lubrication. This mount costs £51 10s.

All three new models, we are informed by the Calthorpe Co., have been subjected to exhaustive tests, and will be ready for delivery next month.

The Motor Cycle, October 22nd, 1914. p470.

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