The Velocette Venom was a 499 cc single-cylinder four-stroke made by Velocette at Hall Green in Birmingham. Built from 1955 to 1970, it became the company’s best-selling flagship and set a 24-hour world record in 1961 that no 500 or single-cylinder motorcycle has beaten.
Velocette Venom at a glance
| Maker | Velocette, Hall Green, Birmingham |
|---|---|
| Production | 1955–1970 |
| Engine | 499 cc single-cylinder four-stroke |
| Developed from | Velocette MSS |
| Launched | November 1955 |
| Built | 5,721 |
| 24-hour record | 1961, 100.05 mph at Montlhéry |
| Thruxton version | from 1965 |
| 1967 | Isle of Man Production TT win |
| Electrics | Miller to 1962, then Lucas |
| Finish | black with gold pinstriping |
Based on one source: the English Wikipedia article on the Venom.
History of the Velocette Venom
From the MSS to a 500 sports single
The Venom was introduced in November 1955 and launched alongside the 349 cc Viper. It was developed from the MSS to compete with a new range of British twin-cylinder motorcycles. Conceived by Eugene Goodman and designed by Charles Udall, its 499 cc engine had a bi-metal cylinder with a cast-iron liner, a high-compression piston and a light alloy head; the high cam with short pushrods was simpler to produce than an overhead camshaft. The model was finished in black with gold pinstriping and plenty of chrome.
Engineering details
The Venom’s clutch sat between the gearbox and the gearbox sprocket rather than in the primary chain case, which made it less accessible but allowed quick gearing changes with a range of sprockets. The constant-mesh close-ratio gearbox could be serviced in place. The frame used single top and down tubes and heavy brazed lugs; at the rear two separate arms were clamped to a cross-tube instead of a welded rear fork, and the shock absorbers moved in curved slots to adjust to the rider’s taste. Telescopic forks were made in-house with hydraulic damping and an offset wheel spindle. Miller electrics were used until 1962, when Lucas equipment took over.
The 24-hour record
In 1961 a factory-prepared faired Venom and a team of riders set a 24-hour world record of 100.05 mph (161.01 km/h) at the Autodrome de Linas-Montlhéry in France. It was the first motorcycle to average over 100 mph for 24 hours, and no 500 cc or single-cylinder motorcycle has broken the record since.
Thruxton and the end
In 1965 the Venom was developed with a full racing kit into the Velocette Thruxton, using a special cylinder head developed by American flat-track racers. The Thruxton won the 1967 Isle of Man Production TT and became the most popular Velocette, but it could not save the company, which went into voluntary liquidation in 1971. The Venom engine was also used in the Indian Velo 500, a limited run of 250 machines devised by the American entrepreneur Floyd Clymer with Italian cycle parts.
Scrambler, Endurance and Clubman
Venom off-road machines were built from December 1954 and sent to America for enduro evaluation. The Mk1 Scrambler used the road frame with alloy mudguards and a high exhaust, the Mk2 of 1958 gained a triangulated removable rear frame section, and the Endurance had a 21-inch front wheel and high bars. From 1960 the Venom Clubman added Amal TT carburettors, a BTH racing magneto, a close-ratio gearbox and a 9.3 to 1 compression ratio, with rearset controls, low bars and a steering damper. It discarded the glass fibre enclosure and showed off polished castings instead.
Design and features
- Record holder: the first motorcycle to average more than 100 mph for 24 hours.
- Pushrod 500: a bi-metal cylinder with cast-iron liner and a light alloy head.
- Unusual clutch: mounted between gearbox and sprocket for quick gearing changes.
- Velocette frame: brazed lugs, two clamped swinging arms and adjustable Girling shocks.
- Clubman option: racing equipment available on a production machine from 1960.
Velocette Venom versions
- Venom (1955–1970): the standard road model, 5,721 built.
- Venom Scrambler (1954–1958): Mk1 and Mk2 off-road machines for America.
- Venom Endurance: off-road model with a 21-inch front wheel and full lighting.
- Venom Clubman (from 1960): Amal TT carburettors, BTH magneto, close-ratio gearbox.
- Velocette Thruxton (1965): racing-kit development, winner of the 1967 Production TT.
The Venom was developed from the MSS and shared its era with the 350 cc Viper. More machines are in the Velocette collection.
Sources
- Velocette Venom, English Wikipedia: development, record, Thruxton, variants
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