Calthorpe was a British manufacturer of automobiles and motorcycles.
The company Calthorpe Motor Co Limited of Birmingham began in 1904 with the production of automobiles.
1911 Calthorpe took the series production of motorcycles on. As a newcomer in this rapidly developing market came at the start motors several manufacturers are used; before the First World War, primarily precision and JAP engines, and later Blackburne and Villiers.
In 1912 took place the motorcycle production in Barn Street. During the First World War hand grenades MK series 5 were prepared.
In the 1920s, Calthorpe designed its own engines, including the model G1. The sale of this model was rather sluggish, so that this model has been modified over several years little. The highlight of the series with experienced Calthorpe Ivory. With a striking color scheme for that time and the modern concept of a coordinated range of 250 cc entry level up to 500 cc was achieved the greatest success.
In the 1930s, economic difficulties led to bankruptcy. Several attempts to revive various investors failed, so that Calthorpe entirely disappeared from the market.
In 1914 the models " 2 Stroke ", " Big 2 Stroke" and " Jap " were offered. Externally, the vehicles hardly be distinguished, because all had a plug- tank and were belt driven. However, each model had a different engine, as the name suggests.
In 1916, the models " 2 Stroke " and " Jap " from previous years were offered in a technically and visually updated form. The first time was also a team with chain drive and two cylinder V- engine from JAP in the program. For the ladies, the model " Ladies" was offered. The low frame and the belt guard allowed a driving with a dress or skirt.
The models were except for a few small modifications and the vehicles offered by 1916.
This year, the motorcycles were built by Calthorpe bulkier and larger. The belt drive was ( 3.5 hp ) replaced due to increased power of the motors by a chain. The vehicles were equipped with 3 -speed transmission. The first time was a "sport" - model with OHV - engine available. For the first time produced Calthorpe own 4- stroke engines.
Calthorpe released in that year produced many vehicles, many of whom were available with Calthorpemotoren. The cheaper models were essentially the models of the year 1925. It but a 2.5 hp motor from Calthorpe (Model A.5. ) Or Blackburne (Model A.5.B. ) was installed. Furthermore, the model was Featherweigth (C.2. ) Produced. The more expensive vehicles "Sport" ( D.6.A. ) and "Super Sport" ( D.6.S. ) differed greatly from the other externally. The rounded tank and the massive 3.5 HP OHV engine Calthorpe given the machine a modern look. A team was also available. A sports model ( G.1. ) With Calthorpe vertical shaft engine ( OHC ) was also offered.
During these years the "Ivory " models were built. They all had a Calthorpe OHV - engine with a choice of 250 cc, 350 cc and 500 cc. Fitted with double port saddle tank and 4 -speed transmission vehicles had modern and sporty. The powerful and reliable engine helped the Ivory Calthorpe to good performance. The machine fell on by their ivory finish, which was not typical for this time of ore. In the five years of production, changes in the Ivory have been made, such as the cylinder head. The most striking is certainly that the engine of the initial stood upright, was later tilted forward (English " slopy ").
With the put on the market in 1937 Calthorpe " Red " series show the company again their skills. The elegant and sporty machines had a powerful Calthorpe OHC engine with dual-port. Three models were available. A 250 - cm ³ -, a 350- cm ³ - and a 500 - cc engine. The bikes were very well equipped and therefore contributed factory marked " De Luxe". Furthermore, a "Special Competition Model " was built. This was a sport motorcycle with raised exhaust and Burma gear. The 350- cm ³ - or 500 - cc engine was increased by a special AMAL carburettors, modified valves and other cylinder head in his performance. To operate with gasoline benzene, or alcohol mixture, the engine is optimized.