the seat post and damped by a hydraulic damper. In the Series D the RFM was redesigned with relocated spring box lugs and a new, single Armstrong spring/damper unit. These changes resulted in a 30% increase in travel to a full . In front the Series B Black Shadows have the same Brampton girder fork used on the Series B Rapide. A 180 lb front spring is fitted on the Series B Shadows, in contrast to the 160 lb units on the Rapide. In Series C and later Black Shadows the Brampton unit is replaced by Vincent's own Girdraulic blade-type girder variation that used a hydraulic damper in place of a coil spring. Another Series C change was the appearance of curved lugs for the seat stays. Brakes, wheels, tyres The brakes on Series B and Series C Black Shadows are dual single leading shoe (SLS) drums front and rear. Unlike the Rapide, the drums are not interchangeable front-to-rear on the Black Shadows. The Shadow drums are ribbed cast iron. The front drum has a small flange and is attached with five bolts, while the rear has a larger flange and is attached with ten bolts. The brakes use Ferodo's MR41 linings, which was new on the Shadows. Instrumentation The primary instrumentation on Series B and Series C Black Shadows is a Smiths chronometric speedometer that from 1949 on was a large unit mounted almost vertically. Speedometers on domestic models are calibrated up to 150 mph, while export models are fitted with a 240 km/h equivalent. Series D Black Shadows do not use the 5 inch speedometer but rather a 150 mph version of the ordinary S576/L instrument. Model history While the Series B Rapide was not designed to be a racer, PCV felt that steady improvement was necessary and drew up a specification for a version with greater performance. The factory had been receiving inquiries regarding tuning options that would increase performance of the existing model, and PCV believed that a new model would offer two things; an upgrade path for owners looking for more speed and increased profits for the factory. Further encouragement was provided by the racing success of factory racer and performance testbed Gunga Din. When PCV proposed the new model to Vincent managing director Frank Walker, Walker refused to authorise development. Engineer Phil Irving and racer and Development shop head George Brown quietly built two