Calthorpe Motor Co of Cherrywood Road, Bordesley Green, Birmingham made cars and motorcycles from 1904 to 1932.
1904 The company began as a Birmingham bicycle maker run by George W. Hands who, in 1904, made his first motor cars, a 10 hp four cylinder model. They briefly made some
larger types but it was in the light car field that they specialised using proprietary White and Poppe
engines. The cars were successfully raced in France in the Coupe de l'Auto series.
Calthorpe produced motorcycles from 1909 to 1947.
The machines were built by the Minstrel and Rea Cycle Co of Barn Street
1909 Late that year, after many successful years in the motor car trade,
the company made its motorcycle debut at the Stanley show. As with their
cars, the motorcycles were fitted with a 3½ hp White
and Poppe engine. They also had a chain-driven Simms magneto, Amac
carburettor, belt drive and Druid
1910 Stanley Show Report
Calthorpe Motor-cycle Works.
Birmingham. Stand No. 52.
The six Calthorpe models illustrate three different patterns of
motor-bicycles. The standard touring machine is fitted with an engine
measuring 86nnn. in the bore and 88 in the stroke. This is rated at 3.75
H.P., and we should think this power is by no means over-estimated. The
valves are, of generous dimensions and are both mechanically operated.
Belt trans- mission is employed with a variable pulley. A Brown and
Barlow carburetter and high tension magneto supply the gas and the means
for firing it. There is a specially designed cut-out on the silencer. A
good deal of care has been bestowed on the tank and its accessories. It
is fitted with large, quickly detached tillers, and a combined filter
and petrol gauge. Lubrication is effected by a drip feed oil pump. Last,
but not least, the frame is designed so as to afford a very low saddle
position. Another specimen is similar to the above, but has a side-car
attached, and is similarly equipped with as L.M.C. free engine and
two-speed gear. Then there is a third with another style of frame even
lower than the first. Probably the most interesting of the lot is the
new Tourist Trophy model. This has a short stiff frame and rigid stayed
front fork. Pedalling gear is, of course, absent, and the foot-rests are
adapted to operate a powerful brake on the belt rim. Weight has been
studiously reduced while maintaining strength and the horse-power per
lb. rating works out very high. The prices are attractive both to the
agent and rider, and the company's motto continues to be " Wholesale,
and to the Trade only."
1912 They used Precision
engines and began to add further models, including a lightweight. Then
came a model with water cooling.
1914 The CalthorpeMinor was produced with a 1.25 engine
and a two-speed gearbox in the crankcase.
1915-1922 A two-stroke model appeared in 1915 - this used a JAP engine. It continued for 1916 and from then on a 2¾ hp four-stroke and 2½ hp two-stroke, both with Enfield gears were built. These continued well into the post-war years.
1922 The two-stroke also became available with a single speed and belt drive as an option. They were then joined by a 350cc two-stroke with a three-speed Burman gearbox and chain-cum-belt transmission.
1923 Another version of that model became available with sidecar. The four-stroke changed to a 249cc sv Blackburne engine and two speeds, with either belt or chain final-drive.
1924 The 245cc two-stroke had a three-speed Burman gearbox; the 350cc version
was dropped and a JAP was used in sv and ohv forms along with a 147cc Villiers
1925 The all-new 348cc Sports model arrived with own-designed engine,
three-speed Burman gearbox, light frame and Druid
1926 A Super Sports version was added.
1927 A 498cc ohc single of their own design appeared.
1928 The company was only using its own engines, with the 348cc in its
two forms. The camshaft model was then dropped.
1929 Saw the arrival of their best known model - the Ivory Calthorpe.
For this they took the 348cc ohv model, revised and modified it, added
a saddle tank and finished the tank and mudguards in off-white.
1930 There was a single-model range. Following the trend of the time, they
gave it an inclined cylinder and listed it as Ivory the Second,
which then went on to Ivory III.
1932 By now there was the 494cc Ivory IV, and for that year only
there was also 247cc two-stroke Ivory Minor.
1933 Only the 494cc model was listed, as the Major.
1934 That model was joined by a 247cc model. Following on came 348cc and
competition versions and those continued throughout the decade.
1937 The firm of Pride
and Clarke of London had exclusive rights to sell the marque, which
had changed its colour to become Red Calthorpe. This change did
not boost sales; the firm went into liquidation and was then bought by
Bruce Douglas, who moved the plant to his company of that name, in Bristol.
1939 In May of that year, Bruce Douglas announced a three-model range using
A few of these were built before the factory turned to war efforts.
1947 After World Ward II the name reappeared as Calthorpe-DMW, on a machine
using a 122cc Villiers engine.
Note: By 1950, the above had led on to the the DMW