RAPIDE'S are better, I've told this story before, but not a clue how to find it or make a link. I visited PCV on numerous occasions, every time I left the passenger / banana boats (SS Golfito or SS Camito) at Southampton, hired a car detoured via Mr Vincent's with the usual offerings of a 40 oz bottle whisky and a stem of bananas. He always took the full bot whisky but only cut off a few hands of bananas! Many discussions, mostly about his new engine, but adaptations for marine concepts (he had a wonderful way of selling you his product to match your requirements), occasionally reminiscing about the works, he said he wouldn't have survived it it hadn't been for the Black Shadow, Why ? they had such a stock pile of crankcases that had all been machined ready to build, but testing them with blanks fitted to all apertures and air pressure applied whilst submerged in water revealed porous cases. The blanking idea only came about when they weighed up the wasted man hours building a complete bike only to find they oozed oil through the castings after road testing. So, typical manufacturer with a poor product, devised a method to seal the cases by submerging them into a vat of shellac, pulling a vacuum, so extracting the air, then releasing the vacuum and the shellac is sucked into the cases, cleaned off and coated with yellow chromate and stove enamelled them black (nice shiny overcoat & piss poor for dispersing heat).
Then make them more attractive, how ?! Speed, revamp it with bigger carbs, ribbed drums, and a five inch windscreen speed-clock.
I've a feeling that the majority of "high" speed machines have been Rapide's, some one most know differently! Occasionally when the demand for B.S. bikes was higher than painted cases they called them White Shadows using Rapide cases. PCV didn't make as much money on a BS because of the work involved. this is backed up with the introduction of the series "D's" with dye cast cases. They were not painted black because the was no necessity to do it, the covers were done just to keep up the theme and save owners the necessity for polishing, but it has to be very good to look good, some tail end "C's" with dye cast were still painted all black. The difference in price is "silly high" get a Rap and spend the difference on it to what "you" want as there are so many standard Vincent's about it's bloody boring,, generally only show pieces for adornment, I do appreciate that they have not been superseded by any other two wheeled machine with such aesthetic beauty only with the "A" Rap is an UGLY ABORTION to what came later, fascination, it's kept me entranced for years. God bless Mr P. Vincent, I wish he had benefited from his achievements along with Mr P. Irving.