By the early sixties, many of those racing a 1000 Vincent came to the same conclusion: the greatest engine ever made for a motorcycle that was by then wearing an unsatisfactory frame for highly competitive racing. No offense: the 1000 Vincent remains, even today, a great touring bike, especially in its later Series D version. However, conceptually the suspension was designed before WWII and only improved post-war, while the conventional telescopic forks and the swinging arm were coming to be adopted by the competition, simply because they were delivering better handling. The Vincent too was by then at least five to ten years old, and the braking and the excess of weight meant it was lagging behind race-track equipment of the time. In fact, even George Brown (1) was advocating such solution when at the 1951 Goodwood meeting, Geoff Duke won the 500cc race nearly 5mph faster than him in the 1000cc race that George won (2).
Consequently, club racers riding a Vincent started to implement all types of modifications: the most radical was to get rid of the Vincent chassis and drop the twin, upgraded to Black Lightning spec, in a Manx rolling frame (3). West Londoner Derek Parkin, who also was racing a standard Vincent, had a different vision. He disregarded the Norvin concept arguing that the center of gravity was not better positioned than in the stock Vincent and also that the frame was anyhow unnecessary. Therefore, the handling, braking and acceleration would not be better than the standard Vincent (4). It is somewhat arguable, as a Norvin used more modern suspension and brakes, however Dennis Curtis (5) made a similar assessment as he also modified the Manx frame to offset these two disadvantages.
So, rather than adding a frame, Parkin focused on shaving weight off the bike, adding modern suspension similarly to George Brown with his Nero, but coming from Norton instead of AJS: a Roadholder fork, which was the benchmark at that time, while the RFM was modified to fit a pair of conventional shocks (6). In the weight-loss race, many chopped the engine to use a racing gearbox like the close-ratio Manx, saving weight for the gearbox and the primary transmission; however, as the Parkin-Vincent maintained the structural engine architecture, Derek Parkin could not chop the gearbox. So, to save weight he cut out the wall between the engine and transmission internals, the same oil lubricating the whole engine. As a consequence of all these changes, the bike weighed just 364lbs, almost 100lb less than a stock Rapide and Parkin claimed a top speed of 140mph.
The original prototype was built in 1962 and Derek Parkin piloted himself the bike. Out of ten events up to 1967, Parkin scored six firsts, three seconds and one third place, so his recipe was obviously quite good. The Vincent Owners Club awarded him the “Eve Neave Trophy” in 1963 for the most outstanding performance during the season by a club member. Parkin began a limited production sold under a “kit” form (7), of around 12 – 14 units. So, a Parkin-Vincent remains a rarity on our roads; around eight are known to have survived, two in the USA and the rest in the UK. In the US, there is a twin based on a Series C belonging to Dale Keesecker, and a Comet based on a Series D belonging to Bill Norton.
Dale said that he found the bike in quite bad condition “Cosmetically, it was horrible, and the tank was crushed on one side.” However, when he started to strip the bike, the engine turned out to be in good shape, so the restoration centered on repairing and colour-matching the tank, reconstructing the seat pan and reassembling the Black Shadow engine. But before doing so, Dale also decided to rebuild the wall between the engine and the gearbox, eliminating one of the Parkin’s signatures. It was likely the most important decision to be made, for the sake of the reliability. Because of its rarity, Dale doesn’t ride the Parkin much, but he says it loves running fast and handles extremely well.
Bill Norton’s story is quite interesting too. When looking for a Comet, Bill focused on the uniqueness of an Egli or a Norvin but eventually he found the rarity in a friend’s garage as a basket case: the remains of a Parkin-Vincent 1000 Series D, imported privately from England in the early 60s. This bike was first bought by Leo Goff, a well-known dragster guy and was loaded with Black Lightning components. Thn Somer Hooker acquired and rode it extensively, before being taken apart. Bill bought the frame with a pair of Comet crankcases as the basis for its new life and says: “the bike turned out to be better that I could have dreamed, it stops very well and with a 600cc engine it pulls top gear on any hill.”
Philippe Guyony © 2014
Many thanks to Dale Keesecker, Bill Norton and David Lancaster who have been very helpful in providing the above information and without whom it would not have been possible to write this article.
(1) George Brown was the Vincent official pilot and also was leading the Vincent experimental shop at the Vincent factory until 1951.
(2) According Charlie Rous, Classic Racer Winter 1990
(3) See the Norvin page https://egli-vincent.net/vincent-specials/the-norvin/
(4) Parkin-Vincent Flyer from Richmond Hill Speed Shop (1967)
(5) See the Curtis-Vincent page https://egli-vincent.net/vincent-specials/the-curtis-vincent/
(6) MotorcycleClassics.com article by Richard Backus | May/June 2007http://www.motorcycleclassics.com/classic-british-motorcycles/dale-keesecker-custom-vincent-motorcycles.aspx
(7) There are no official records for the production but according Bill Norton who had the chance to meet Derek Parkin at the Isle of Man in 1999 during the VOC International; Derek told him to have built between 12 and 15 in “kit” form only (the Vincent UFM was preserved and thus the vehicle VIN#).