c1925 Diamond-Villiers Ultra Lightweight 147cc Solo Motorcycle (Project)

Description

D. H. and S. Engineering in Wolverhampton (UK) began production of its Diamond bicycle in 1899 before expanding to motorcycles production, which ran between 1908 and 1933. Diamond launched a range of four motorcycles initially, powered by Belgian FN single cylinder and V-twin engines, though minus the usual shaft-drive associated with that Liege firm. The two singles of 2.5hp and 3.5hp and two V-twins of 3.5hp and 5hp had the rear cylinder positioned vertical, 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 the appearance of the era and of limited production. In 1912 an advanced Diamond model was introduced with a 2.75hp engine but the valve gear and transmission both were a major departure from the norm. The valve gear had an oh inlet above a side exhaust, both at the front of the engine, while the camshaft ran forward along the right side of the engine and was driven by a bevel gear on the end of the crankshaft, which extended to the magneto at the front 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. Further developments emerged during this period of motorcycle technology evolution, with JAP, Villiers, Blackburne, Barr and Stroud and oil-cooled Bradshaw engines all being utilised by Diamond in capacities ranging from 147cc to 500cc. The Diamond Ultra Lightweight model of 1925 used a 147cc Villiers engine and was a basic commuter machine of its day, and the last of the chain-cum-belt bikes built. By 1933 only one Diamond model was produced, and in 1935 motorcycle manufacturing was abandoned altogether as firm’s attention turned to the production of milk-floats and trailers.