Vincent Black Shadow and C bikes having 1⅛" Amal 289 carburettors and Series D bikes having 1⅛" Amal Type 389/10 units. While other contemporary motorcycles tended to be polished and chromed, founder Philip Conrad Vincent (PCV) decreed that the Black Shadow engine itself be black. The engine's signature colour was achieved by applying a "pyluminising" coating of chromate anti-corrosion primer over which a layer of Pinchin & Johnson black enamel was added. The part was then baked in an oven for 2 hours at . Although some have claimed that the black finish increased the rate of heat rejection from the engine, its
Vincent Black Shadow bolted to a slightly modified version of the Series C malleable iron steering head casting. This revised UFM no longer carries oil and so a separate oil tank is fitted. Due to extensive use of aluminium alloy, weight for the complete bike is kept to a relatively light . The standard handlebar on all models of HRDs and Vincents is the black enamelled `HRD straights'. Series B and C bars are 7/8 inches in diameter and 25 inches long with the ends bent back at 20°. Series D bars are 1½ inches longer. The Black Shadow could be had in