1961 Velocette Venom 500 Clubman

The Venom

The Venom had its origins in Velocette’s 1933 250cc MOV, which was intended as a sporting lightweight to fill the gap between the utilitarian 250cc GTP 2-stroke and the 350cc overhead cam KSS street bikes. It was to be easier and cheaper to produce, but still reflected Velocette’s engineering sophistication. So while the specification called for pushrod-operated overhead valves, designer Charles Udall placed the camshaft as high as possible in the engine to reduce moving mass in the valve train — leading to the famous “Map of Africa” timing cover. Udall also tried to minimize the width of the crankcase and therefore reduce flexing. To achieve this, he specified a taper-fit crankpin to avoid using lock nuts, and taper roller main bearings. Udall also kept the primary driveline chain as close as possible to the crankcase, minimizing side loads on the crankshaft and gearbox mainshaft. This allowed the clutch to be inboard of the countershaft sprocket, meaning the final drive gear ratio could be changed in minutes.

The MOV’s design became the template for all Velocette overhead valve singles, and its fundamental sturdiness was demonstrated in that the same basic bottom end was retained throughout the engine’s evolution. But the most popular engine size for a sporting motorcycle in 1930s Britain was 350cc, so the 68mm x 68mm MOV acquired a crankshaft with a 96mm stroke to create the sporty 350cc MAC of late 1933. The sidecar-tug market was also important in the 1930s, so Velocette responded with an 81mm bore for more torque, creating the 500cc MSS.

Phil Irving of Vincent fame joined Velocette in 1937, and was principally responsible for modifying the MAC for wartime use as the Velocette MAF.

The MAC and MSS were reintroduced in 1946 following the end of World War II and fitted with Dowty Oleomatic semi-hydraulic forks in 1947. The MSS disappeared from the Velocette range in 1948 while Velocette concentrated on their revolutionary LE model. The MAC continued with major changes: For 1951, a new Velocette-made hydraulic front fork replaced the Dowty; an iron-lined “Alfin” cylinder and light alloy head were fitted; and in 1953 a swingarm frame arrived. The new frame featured a slotted track for the upper rear shock mounts, so that the shock angle could be adjusted (thus varying the preload) by sliding the top mounts back and forth through a short arc.

The MSS rejoined the lineup in 1954, but with cylinder dimensions revised to give a “square” 86mm x 86mm bore and stroke. The reason, designer Charles Udall famously stated in an interview, was not because shorter strokes were necessarily better, but because that was the longest stroke that would allow the MSS engine to fit in the new MAC frame! At the same time the MSS also got an Alfin cylinder and alloy head.

While the MSS and MAC continued the Venom and Viper performance versions arrived for 1956. Power output for the 500 went from 27 horsepower at 5,500rpm to 36 horsepower at 5,700rpm, with top speed claimed at 102mph thanks to a revised camshaft, larger Amal Monobloc carburetor and compression increased from 6.8:1 to 8:1. (The Viper’s 350cc engine used the same stroke as the 500, but with a smaller bore of 72mm.)

Included in the Venom’s specification were hairpin valve springs. (Udall claimed the resonant frequency of coil springs could cause valves to float.) The camshaft operated quadrant-shaped followers working the rockers via short pushrods. The crankshaft was located in the cases by taper roller bearings that were shimmed to a slight preload during assembly to control side play. Drive to the 4-speed gearbox (featuring the sequential foot-change that Harold Willis invented for Velocette in the 1930s) was by chain as for the MOV. The Venom also retained magneto ignition and Velo’s characteristic belt-driven dynamo. Important new features were full-width brake hubs carrying 7-1/2-inch single-leading-shoe front and 7-inch single-leading-shoe rear brakes.

Clubman: By name and nature

Velocette’s next development of their big singles was likely spurred by the popularity of Clubman racing in the U.K. A number of disused World War II airfields like Thruxton in Hampshire, Castle Combe in Wiltshire and Snetterton in Norfolk were repurposed as race tracks. British champions like John Surtees and Mike Hailwood got their starts racing at such circuits in Clubman amateur races, and the first choice bike for many Clubman racers was BSA’s mighty DBD34 Gold Star.

Hinting at greater sporting potential, the Venom and Viper had both received lighter flywheels and larger carburetors in 1956. In 1957, a prototype sports version of the Venom with higher compression was entered in the 24-hour Bol d’Or race, placing third overall and first in class. But it took until 1959 for the new bike to emerge from the factory as the production Clubman. All the parts to build your own Venom — or Viper — Clubman had been available as components from the factory.

So the Venom Clubman was fitted with a BT-H racing magneto, an Amal 10TT9 racing carburetor, rearset footpegs and a reversed shift lever (with the internal selector reversed to maintain the existing shift pattern), a new header and muffler (for improved ground clearance), close-ratio gears, a Nimonic alloy exhaust valve, aluminum alloy wheel rims and modified fork internals for two-way damping. Also included was a tachometer and racing seat. An increase in engine compression to 8.75:1 was achieved by removing a compression plate spacer and fitting a solid skirt piston. As such, the Clubman came close to the BSA Gold Star’s power and weight (39 horsepower and 375 pounds dry versus the Gold Star’s 40 horsepower and 380 pounds dry), and thanks to different power characteristics, it was reportedly faster in a straight line.

As intended, the Clubman was particularly effective in endurance racing, and while it never won the Southampton & District Motor Cycle Club’s prestigious 500-mile race at the Thruxton circuit outright, it was second in the 500cc class four times, and first in class in 1964.

In 1960 Velocette joined the then current fashion for body enclosure, with molded plastic bodywork covering the lower engine and transmission on both sides of the Venom and Viper. It’s also supposed this was a cost-saving measure, reducing plating and polishing expense. Fortunately, the Clubman avoided this indignity and continued with its polished engine cases exposed.

However, the Clubman and the other big singles were available from 1960 with a Veeline dolphin fairing from Mitchenall Brothers based on the fairing used on the 24-hour bike.

The Ultimate Clubman

Velocette celebrated its 1964 victory at Thruxton by announcing a new model — based on the Clubman and named for its successful race venue — for 1965. Among many modifications, the Thruxton included larger valves with reduced valve angle, longer intake tract, a 35mm Amal 5GP2 carburetor, 9:1 compression piston and revised valve train.

The front fork was derived from the MSS-S Scrambler, and the 7-1/2 inch twin-leading-shoe front brake was from John Tickle. The longer intake and GP carb led to the Thruxton’s trademark cutout in the gas tank. With 41 horsepower at 6,200rpm, the Thruxton was good for 120mph with race exhaust, and it put this power to good use, taking first and second places in the inaugural 500cc Isle of Man Production TT in 1967.

The last Clubman left the Velocette factory in 1970, and the last Velocette of all — a Thruxton — in 1971. Veloce Ltd. went into voluntary liquidation that same year. In all, some 5,750 Venoms were built between 1956 and the end of production.

Velocette’s big singles in general — and the Clubman in particular — were never sold in the kind of numbers that BSAs, Triumphs and Nortons were, and for very good reasons. Designed for ruggedness, longevity and reliability, and to a higher quality finish, engineering was rarely if ever compromised for cost reasons (although later Venoms did use a cast-iron cylinder in place of the more expensive “Alfin”). That meant they were typically more expensive than other British bikes, but required less maintenance. Overall, they were capable of covering great distances at high speed with little fuss.

Wrote Motor Cycling magazine in a period test: “The Velocette Venom Clubman Veeline is a mount with which to enjoy hard riding, Capable of handsomely breaking ‘the ton,’ it can keep going at high speeds as long as fuel or rider permits … Here in fact is a true thoroughbred.”

Don Smith’s Clubman

Don Smith of Appleton, Wisconsin, acquired his 1961 Venom Clubman through a chance phone call to an old work buddy, Jim Wadkins.

“I asked him if he had any motorcycles, because 40 years ago he rode,” Don says. Jim admitted he had stopped riding because of failing eyesight, so Don asked him if he had any bikes at all. “He says, ‘Yeah, I’ve got a Velocette in the garage that I haven’t ridden in 30 years.’ So we talked a little, but I didn’t know anything about Velocettes.” Don asked if he was interested in selling. Jim said no. “Well, what are you going to do with it?” Don remembers asking.

Don researched the Velocette marque, and was also able to put together some provenance on Jim’s Velo by contacting vintage restorer and Velocette specialist Richard Renstrom of Classics Unlimited, who had sourced the bike from the U.K. and sold it to Jim. Don also collected period tests and reviews, as well as finding a copy of Always in the Picture by R.W. Burgess and J.R. Clew, the definitive history of Velocette. All this helped Don decide that he really wanted his old buddy’s bike. “I told him I was looking for a bike to restore,” Don says. But the response he got was that the bike didn’t need restoration.

More phone calls over many months eventually persuaded Jim to sell the Clubman to Don. And when Don finally got the Velo, he discovered that Jim was right — the Clubman didn’t need restoration; just cleaning, polishing, fresh fluids and some TLC. Don credits help from a Finnish friend, Pekka Helen, for getting the Velo going.

First they cleaned the magneto to ensure a good spark. “I knew nothing about Velocettes,” Don says. “We cleaned the carb, changed the oil and filter, kicked it over many times and finally blew out years of mouse habitat!”

Don is delighted with his acquisition, and though Velocettes have a reputation for being hard to start, Jim says it comes down to doing it right: “I follow the procedure and it starts first kick,” he says. MC