38 :OLD BIKE AUSTRALASIA
Then came a second challenge – the fabled
Velocette Roarer, but at least one example of the
supercharged 500 twin that completed a solitary lap
on the Isle of Man TT course in 1939 existed in the
hands of Ivan Rhodes in UK. Dan was able to take
measurements and compared notes with Ivan, but
it was still an immense project, which was detailed
in issue 76.
Now to complete the trio we bring you the story
of how Dan Smith came to create a replica of the
Vincent H.R.D. Series A Rapide, a machine for which
he holds great affection. Like the AJS and the
Velocette, Dan chose not to slavishly copy the
original, instead incorporating some modern internal
components and taking advantage of the availability
of materials that were not in general supply nearly
80 years ago. And unlike the other two bikes, this
one was going to be ridden, and ridden regularly,
because Dan and his wife Eileen are keen tourers,
having covered hundreds of thousands of miles
across several continents on a variety of machines,
including his 1949 Vincent Rapide.
Not for nothing is the pre-war Rapide known as
the “Plumber’s Nightmare”, with external oil lines,
hoses and so on running everywhere. But in many
ways, this jumble of ‘plumbing’ adds to the
machine’s appeal – it certainly did for Dan. At this
point, a little background is relevant.
It would have been a relatively logical step for
Philip Conrad Vincent (known to his friends as PCV)
to simply slip into the family cattle business, which
was based in Argentina, but during his education at
Harrow, became increasingly drawn to motorcycles,
and especially their design. Even before he
graduated, he had designed his own frame with
rear springing, using a triangulated pivoting
structure. This was to remain in basically the same
form until production of the motorcycles bearing his
name ceased in 1955. By 1926 he had drawn up
several motorcycles, but converting them to metal
was another matter. With financial assistance from
his parents, one of these was built, using a 350cc
MAG engine, upon which young Philip clocked up
a considerable mileage. With a further injection of
family money, a company was formed and premises
formerly occupied by the carriage builders Ottfords
at Stevenage, north of London, acquired.
By now it was 1928, the same year that successful
racer Howard R Davies decided to relinquish the
company he had formed in 1925 to manufacture his
own motorcycles. Aboard his own HRD, Davies had
sensationally taken victory in the 1925 Senior TT, a
win that instantly elevated him to legendary status.
When Davies took the decision to cease trading, he
found a ready buyer for the business in young Philip,
and production was transferred to Stevenage. Philip
Vincent wisely chose to use the HRD brand (at least
initially) as it was a proven product, rather than go
through the travails of launching a new brand
(Vincent) on a cautious buying public. A variety of
motorcycles was produced, albeit in quite small
numbers, using engines from MAG, Blackburne, J.A.P.,
Rudge and Villiers (and even one with a Cross Rotary
valve head). Although J.A.P. was the favoured power-
plant, Vincent was dissatisfied with the qualitycontrol, and in 1934 Rudge announced they would no
longer supply engines to other manufacturers, so it
was time for a re-think. In 1931 PCV had engaged the
services of Australian Phil Irving, who had coinciden-
tally arrived in Great Britain from his native Victoria
on the pillion seat of a 500cc HRD ridden overland by
John Gill. Irving’s practicality was the perfect foil to
Vincent’s adventurous attitude to design, and the first
original fruit of Irving’s labour was a fairly conven-
tional single cylinder overhead valve 500, with a
high-mounted camshaft, released in standard form as
the Meteor, as the Comet in sports trim, and as the TT
Replica in full racing specification. Irving says the
selection of the bore and stroke for the new engine
was conceived in a novel way. “84mm was the small-
est cylinder I could get my hand into for cleaning, and
as Vincent did not like long-stroke engines, the stroke
chosen was 90mm, giving 498.7cc.”
The new 500 was very well received – fast and
reliable – and set Vincent’s ever-active mind upon the
next project. It has gone down in motorcycling history
that the engine that followed the 500 single came
about as a result of happenchance. Irving was work-
ing at his drawing board on the timing side crankcase
half of the 500 engine, and by turning over the trac-
ing paper and superimposing it on the main drawing,
he found himself staring at what was in effect the
layout for a vee-twin with a 47-degree included
angle between the cylinders. This meant that the
second cylinder’s camshaft could be driven by the
idler gear already used for the first. He went on to
say, “Translating the idea into reality was not as
simple as it looked during the first fine careless
rapture of discovery, but the simple plan of offsetting
the rear cylinder 1 1/2 inches to the right permitted
its exhaust pipe to clear the front cylinder, and
allowed two standard con-rods and big-end assem-
blies to be mounted side-by-side on a long crankpin.”
Apart from new, wider crankcases, the twin used
the same engine components as the single, with
both exhaust ports facing forward. The frame was also
similar to the Meteor, although lengthened by three
inches. The new twin was named the Rapide, and the
prototype was completed (with the exception of theVINCENT SERIES A RAPIDE
TOP LEFT Post-war stopping power. LEFT Oil tank sits
where toolbox once lived. The tool box is now
under the seat.ABOVE Fuel tank was modified from
Series B item.ABOVE RIGHT Hand made badges.
“There’s 9 troy in each of those tank badges!”
RIGHT Magnetos are a tight fit. FAR RIGHT Modern
tubeless tyres on specially sealed rims.“Translating the idea into reality was not as simple as it looked
during the first fine careless rapture of discovery...”
The fabled yellow-faced
instruments adorn Dan’s bike.