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Velocette "Venom Clubman Vee-line" 1961
1961 "24-HOUR RECORD" VELOCETTE. Although the Velocette "Venom
Clubman Vee-line" was sold as a sports roadster, that could be employed in
production machine races, it was one of these machines—actually the prototype
for this model—that on March 18-19, 1961, became the first motorcycle in the
world to average over 100 m.p.h. for 24 hours.
This amazing feat of endurance was accomplished at Montlhery
track in France by an Anglo-French team of eight riders in which the British
spearhead consisted of Velocette sales director Bertie Goodman and Motor Cycling
staff writer Bruce Main-Smith.
As will be seen, no lights were fitted to the machine, and during the hours of
darkness the model had to be raced under conditions virtually the equal of poor
street lighting, on the very bumpy Montlhery circuit, a really arduous test of
riders and machine.
Design of the power unit was similar to that of all push-rod
Velocette singles made from 1932 onwards. A gear train drove a camshaft mounted
high up in the timing case and short push-rods, with consequent low
reciprocating weight, operated the rockers. The ."Venom" motor employed hairpin
valve springs, fully enclosed, and the very narrow crankshaft assembly was
mounted on Timken taper roller main bearings.
Close-ratio gears were used, with a 4:1 top, and the kickstarter was removed. A
KTT-size megaphone was fitted to the exhaust pipe and an "Avonaire"
dolphin-style fairing was used, with interior panels directing the air blast
into the cooling fins of the head and barrel.
Apart from fuel and oil tanks (both slightly bigger than standard), this
machine, which gave such an important boost to British motorcycling prestige,
was in virtually "over the counter" trim, with the engine developing 398 b.h.p.
at 5,900 r.p.m.
SPECIFICATION
Engine: single-cylinder 500 c.c. o.h.v.; valve operation by high camshaft and
short push-rods.
Ignition: B.T.H. magneto.
Transmission: chain via four-speed gearbox.
Frame: cradle type with single down-tube and twin bottom rails; pivoting-fork
rear suspension controlled by hydraulically damped Girling units, adjustable for
load in patented frame slots.
Forks: telescopic.
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