A Revisionist View Of Vincent Motorcycles

We can stop insisting they were perfect.

Vincent Series B
“What have they done with the frame?” Motorcyclists might have asked this question upon seeing a Vincent Series B for the first time. Conventional downtubes were abandoned, and the engine and transmission were used as stressed members, hung from a large-section backbone doubling as an oil tank.Veloce Publishing

Vincent enthusiasts I have known committed the lore of the brand to memory and were always ready to defend each and every feature of Vincent design as if they had been divinely inspired. Indeed, Phil Vincent and his sometime engineer/enabler, Phil Irving, did bring forth highly significant innovations. First among them was the triangulated swingarm rear suspension added soon after Vincent bought the HRD brand from Howard R. Davies in the 1920s. Another was the chassis-less construction of the postwar Series B Rapide, cited by the late John Britten as inspiration for the carbon structure of his own big twin. Sadly, cults of the iconic can be carried by their fervor considerably past the truth to an extreme position that insists useful motorcycle innovation ceased when Vincent’s company closed in the 1950s.

It was therefore a breath of fresh air to encounter Philippe Guyony’s book, Vincent Motorcycles—The Untold Story Since 1946, published by Veloce. Guyony clearly demonstrates his love of the make by having produced this photo-filled 400-page book of nearly 5 pounds weight. He insists upon telling the truth: that by 1950 what had been praiseworthy suspension since Vincent introduced it in the mid-1930s had fallen behind.

Vincent Motorcycles—The Untold Story Since 1946
Vincent Motorcycles—The Untold Story Since 1946 comprises eight chapters, filling 400 pages of text and photos. The book was a journey for author Philippe Guyony. “When I started riding in 1978,” he writes in the foreword, “I had only a vague idea of what a Vincent was.”Veloce Publishing

“While the engine was surely the most potent on the market, the chassis was aging very quickly compared with the ‘super handling’ of some 500cc Grand Prix motorcycles—the Norton Manx and Matchless G50, for example. It did not take long before fellow Vincent racers started to cut and paste components from other bikes, or from the aftermarket, at high cost so that Vincent could remain ‘the world’s fastest standard motorcycle.’ ”

The truth of this was underlined by the results at the 1951 Goodwood meeting. As expected, Vincent employee and racing stalwart George Brown won the 1,000cc class, while Geoff Duke on the twin-loop “Featherbed” Manx Norton single won the 500cc. The shock was that Duke’s speed was 5-mph faster than Brown’s on a bike with half the displacement. Lest anyone be tempted to dismiss Brown as “just a factory tester,” know that he was offered a factory Norton ride by that company’s racing chief, Joe Craig.

The coming of the short-stroke Manx in 1954 made many rolling chassis available at affordable price. The result was the “Norvin,” a Vincent 1,000cc V-twin tightly fitted into a Featherbed Norton chassis. No less a figure than John Surtees (and his father Jack) bought a Manx roller from sidecar champion Eric Oliver. They rebuilt and installed in the Manx chassis Jack’s blown-up Vincent twin, updated with a pair of Grey Flash big-port cylinder heads.

Motorcycle enthusiasts have for years known of the Egli Vincent, which is a Vincent engine in a chassis built by Swiss rider/engineer Fritz Egli. In early days, Egli attempted the Swiss hill-climb championship, in 1965 concentrating on engine power but without result. Switching his attention to suspension and braking, he set aside the stock Vincent girder fork in favor of a Matchless G45 front end and conical-hub brake. This, although an improvement, got him no higher than third in the ’66 championship.

Rider feedback is essential because it is the motorcycle telling the rider how close they both are to the limit.

Forced to widen his thinking, Egli, Guyony writes, “started to analyze more closely what the problem was. Soon he reached the conclusion that there were too many components in the front end, resulting in too much flex under stress, and no rider feedback.”

Rider feedback is essential because it is the motorcycle telling the rider how close they both are to the limit. Egli also saw that, “The contact surfaces of the cylinder-head bracket to the upper frame member were too small.” Mind you, this is not to imply that the original design, adequate for fast roadwork, was wrong. It was just that Egli could not win the Swiss championship with it.

He then designed an all-new chassis based upon a large 4-inch backbone tube, transmitting twist forces from the steering head, back over the engine and down a pair of beefy struts to the swingarm pivot, where use of the original Vincent tapered roller bearing was retained. To this, he added Ceriani suspension and Fontana brakes. With this bike in 1968 he achieved his original ambition: to win the Swiss hill-climb title.

As Guyony explains, this devotion to the brand arises from the then-unmatched broad torque and power of the Vincent twin. In the 60-odd years since Vincent ceased production, enthusiasts and builders all over the world continued to explore the original intention: to combine light weight with high power. The stories of many of their special motorcycles fill the pages of this book.