Vincent Black Shadow "White Shadow" models to the same mechanical specifications as the Black Shadows but with an engine that was polished rather than enamelled. White Shadow engines had a prefix of "1A/". In 2007 the Vincent H·R·D Owners Club commissioned the VOC Spares Company Limited to build a replica Black Shadow from new parts. The goal of the project was to prove that all parts were in stock and available from the VOC Spares Company Limited. Having received glowing reviews from the motorcycle press in the UK, the machine was auctioned by Bonhams and eventually went on display at a museum in
Vincent Black Shadow engine's ports. Early Black Shadows have a third inner valve spring not shared with the Rapide, but this feature was dropped from later bikes. Due to the low-octane 'Pool' petrol that was all that was available in the early post-war years, bikes of the period could have only low compression ratios. Although the prototype Black Shadow was built with a compression ratio lower than the Rapide's nominal 6.8:1, production Shadows have a ratio of 7.3:1 due to having different pistons from the Rapide, although still supplied by Specialloid. The Black Shadows have different carburettors than the Rapides, with Series B