Diamond Motorcycles

Today in Motorcycle History

Diamond Engineering Co

Diamond Engineering Co of Sedgley Street, Wolverhampton

Diamond motorcycles were produced from 1908 to 1933.

D. H. and S. Engineering of Sedgley Street, Wolverhampton, began by producing the Diamond bicycle before moving on to motorcycles.

1899 and 1908. H. and C. Diamond Cycle Co of Wolverhampton. Seen at the National Cycle Collection.

1908 A four-model motorcycle range was announced by D. H. and S. Engineering who then went on to become Dorsett, Ford and Mee or D. F. and M.

Sales were handled by the Victoria Trading Co of Lamb's Conduit Street, London. The four motorcycles were fitted with Belgian FN engines, minus the usual shaft drive associated with that firm. The two singles of 2.5hp and 3.5hp and two V-twins of 3.5hp and 5hp, with the rear cylinder positioned vertical. All had a Bosch magneto and an FN carburettor. Most had sprung forks and all the models were long and low. With direct-belt drive and French grey finish, the machines were typically primitive in appearance and of limited production.

1912 Late that year, an advanced model was announced. It had a 2.75hp engine but the valve gear and transmission both differed greatly from the norm. The former had an oh inlet above a side exhaust, both at the front of the engine. The camshaft ran forward along the right engine side and was driven by a bevel gear on the end of the crankshaft which extended to the magneto at the front of the crankcase, and was fully enclosed. The crankshaft bevel also drove a second shaft that ran back via a cone clutch to a housing with two sets of bevel-gear pairs, thus providing a two-speed gearbox and a means of turning the drive. Final drive was by an enclosed chain. Fitted with Druid forks, the rest of the machine was more conventional, although the rear chain-stays ran straight forward to pass either side of the crankcase just below the cylinder and thence to the downtube.

1913 Early that year, the magneto was turned to fit across the frame to introduce a further beveled pair. The model ran on for a couple of years more.

1914 Directory lists them as Diamond Engineering Co., Limited, Sedgley Street, Wolverhampton and as motor cycle manufacturers.

1915 The model was now joined by another with a 269cc Villiers two-stroke engine with two-speed gearbox and belt final-drive.

1916 Another model appeared and this had a 2.5hp JAP engine.

Post-World War I. The company moved to Vane Street, Wolverhampton, and continued with the same two models. They entered the TT for several years, but were not successful. The range expanded with the use of further Villiers, Blackburne and JAP engines, plus a Barr and Stroud and an oil-cooled Bradshaw.

A report on the 1924 Motor Cycle Show

D. F. & M. [has a] comprehensive range of this company's motor cycles, some fitted with Villiers engines, and others with J.A.P. engines, is shown on the stand, in sizes ranging from 147 c.c. to 500 c.c. The most interesting, perhaps, is that which is known as the Alec Bennett model, named after that well-known rider, and equipped with 172 c.c. two-port Villiers engine.

It may be remembered that a machine of this type was the only two-stroke machine of its type entered in its class in the 1924 T.T., which it won. Another model of interest to readers of this journal is the 500 c.c. sports which has a three-speed gear, clutch, kick-start, and chain drive.

The D. F. & M. Engineering Co., Ltd., Diamond Works, Wolverhampton.

Motor Sport Magazine

1927-1928 The company returned, building only two-strokes before halting production.

1930 Located in St James' Square, the make returned with a single 247cc two-stroke. This was then joined by others including two fitted with overhead-valve JAP engines.

1933 Only one model was produced and this had a 148cc Villiers engine. After that the company returned to the production of milk-floats and trailers.

Note: In 1935, production of the Graiseley pedestrian controlled electric truck began. It initially proved popular as a cheap milk delivery vehicle, but then found uses in hospitals, factories, and warehouses, where its fumeless, noiseless and economical operation made it an ideal form of transport.

Sources: Graces Guide, Motor Sport Magazine

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