998cc Black Shadow - A fine motorbike

998cc Black Shadow - A fine motorbike
In our motorcycle-besotted, pre-license teen years, my buddies and I traded hyperbole like marbles. A Gold Star would do 90 miles per hour in first gear; a 650 Panther revved so slowly, it only fired once every streetlight; a 500 Velocette would pitch you over the handlebars if it backfired while you were kick-starting it. We knew these things to be true because "real" bikers told us so. But there was one machine no one lied about; they didn't have to. From 1948 until the Vincent Engineering Company produced its last motorcycle in 1955, the 998cc Black Shadow was the fastest production two-wheeler you could buy. Period.

Speed hadn't always been Philip Vincent's main goal. As a Cambridge University student in the 1920s, he designed and patented a pivoted-fork rear suspension featuring springs mounted under the seat. It's the forerunner of every modern motorcycle rear suspension system.

Intent on getting into manufacturing, Vincent bought, with his family's help, the remains of the defunct HRD company. These prestigious initials were those of Howard R. Davies, the only rider ever to win the Senior (500cc) TT riding a Junior (350cc) bike. Achieving this feat in 1921 on an AJS, Davies won the Senior again in 1925 on a 500cc bike of his own manufacture. When Vincent bought the business in 1928, the HRD name was its most valuable asset.

Fate next took a hand. One John Gill commissioned from Vincent a motorcycle that he and Walter Stephens would ride around the world. Stephens quit in Australia and a young engineer, Philip Irving, replaced him. Back in the UK, Vincent and Irving formed the working partnership that would create their greatest motorcycles.

Series A

Market response to Vincent's ingeniously sprung bikes was underwhelming, so he turned to racing, entering a team of proprietary engines made by the London firm of John A. Prestwich, branded as JAP, in the 1934 Senior TT. All retired due to engine trouble, persuading Vincent he needed his own engine. The Irving-designed Series A 500cc singles that arrived late in 1934 were named the Comet and Meteor to denote different tune levels. The high-camshaft single used external hairpin valve springs, iron head and barrel, and a Burman gearbox. The 84mm x 90mm bore and stroke would be common to all Vincent motorcycles.

Though his contributions were many, Irving's stroke of genius was realizing a 47-degree V-twin could be built on a modified series A crankcase using the single's "idler" timing gear to drive a second camshaft. The barrels and heads would also fit if the rear cylinder exhausted forward instead of back. Many of the same machine tools could be used. Fanciful accounts suggest a breeze from an open window disturbed the drawings on Irving's desk, laying one over another at the requisite angle. I prefer to think the 998cc series A Rapide was an inspired feat of production engineering.

Unfortunately, the 45hp engine also looked like it was assembled from two singles, with its bewildering number of external oil and fuel lines earning the soubriquet "Plumber's Nightmare." But it was fast: no motorcycle except perhaps Brough's SS100 came close to matching the Rapide's performance.

Series B

Post-WWII, Vincent presented a completely new machine for 1947  -  unlike most British bike makers, who offered warmed-over 1930s bikes.

Gone was the open diamond frame and bewilderment of external oil lines: a massive box section tube doubled as the oil tank and steering head mount. Rear suspension was bolted to the unit construction, 50-degree V-twin powertrain, which now formed a stressed frame member. Inside, the engine was similar to the A, but it drove a Vincent 4-speed gearbox through a Vincent servo clutch. Carried over from the A were the dual front brakes and Brampton fork, but numerous innovations were added, such as the rear wheel with two brake drums/sprockets (gearing could be changed by reversing the wheel without wrenches!), seat struts that doubled as a suspension damper, and hand-adjustable chain tensioners. The series B Rapide deserved to be  -  and became  -  an instant classic.

Series C

Wearing Vincent's Girdraulic forks, the 1948 series C Rapide offered much improved lateral strength and a combined trail/preload adjuster for sidecar use. Tuned 55hp Black Shadow versions of both the series B and C twins were sold from 1947 with larger carburetors, black enameled engine cases, and higher compression. These featured the famous "Shadow Clock" 150-mph Smith's speedometer. Vincent also produced 500cc singles, essentially twins missing the rear cylinder, in Meteor, Comet and racing Grey Flash forms.

Vincents were never wildly successful in circuit racing, although their straight-line prowess was formidable, and the most famous records were those of Rollie Free on the prototype Black Lightning. Meanwhile, Vincent's finances, never strong, suffered several hiccups. Rescued from bankruptcy in 1949 and restructured in 1952, the company also revised its brand to avoid confusion with "H-D" in its all-important U.S. market. Late in 1949, the Vincent logo replaced HRD. That year, Phil Irving left the company.

Series D

The final Vincents appeared in 1954 with major revisions: coil ignition, Amal Monobloc carbs, improved engine breathing, and a hand-operated center stand. Gone was the box spine/oil tank and dual-sprocket rear wheel, while a new rear sub-frame carried the fully sprung dual-seat. At first, the twins were sold in black fiberglass bodywork as the Black Knight and Black Prince, but naked Rapide and Shadow versions were later re-introduced. Motorcycle production ceased in 1955 and the company was sold in 1958.

Epilogue: Fritz Egli's Vincent

Since motorcycling's earliest years, experimenters have built specials around other people's engines; indeed, that's pretty much how the European industry started. Norton, Royal Enfield, even "the Rolls-Royce of motorcycles"  -  Brough Superior  -  used proprietary engines. So when Fritz Egli started racing Vincents in the 1960s, he was following a well-worn path in wanting a stronger, lighter chassis to match the 75-plus horsepower he was squeezing from the incomparable 998cc V-twin.

Shrewdly, Egli retained Vincent's key concepts  -  the engine-as-a-stressed-member oil-bearing spine frame and monoshock rear suspension  -  but engineered them better. The spine became a 4-inch steel tube instead of Vincent's welded box. Around this, Egli built a sub-frame using only straight 1.25" diameter steel tubes on the basis that "unbent tubes have most stiffness." On his Egli-Vincent, Fritz won the Swiss over-500cc championship in 1968. Co-conspirator Fritz Peier took the Egli to England and raced it at Mallory, Oulton Park, and Silverstone. A legend was born.

No two Egli-Vincents are alike  -  a wide selection of cycle parts have been employed, depending on personal preference and availability, and most bear the stamp of their owner. Dennis Delzer acquired his Vincent from California Vincent guru Dick Busby. The engine features gas-flowed, dual plug series "D" heads with 8:1 compression and a lightened valve train fed by a pair of Mk2 Amal carbs. It uses a Ducati clutch and rear hub. Delzer machined a new rear axle and fabricated a new chainguard to suit. Rear fender and kickstand are both modified Triumph components. The rear shock is a 12-way adjustable Spax unit.

Delzer concealed all electronics  -  including regulator, Boyer electronic ignition and coils  -  under the hump of the Bates seat, while a Kubota alternator modified by Vincent specialist John McDougal provides the volts. Delzer also made his own rear-set foot controls, and craftily welded the long kickstart lever from two Honda 750 components.

At the front, Egli Racing clear-coated magnesium alloy fork shrouds and yokes carry 38mm Ceriani stanchions with Progressive springs and two Grimeca calipers. These are topped with Black Lightning instruments set in a stainless mount, while the vestigial megaphone "mufflers" are by Aircone.

A stock Vincent has the allure of a machine designed by an engineer on the principle that if it works right, it'll look right. Stripped of its road-duty peripherals, the massive V-twin lump looks even more imposing  -  especially in black. Hung from Egli's neatly triangulated frame and adorned with Delzer's quality ancillaries, it becomes a lithe, purposeful-looking package, perhaps less poised than a Black Lightning, but with a more assertive stance.

Innovative and idiosyncratic, Vincent always went its own way. Pioneering the use of light alloys, making the engine part of the frame, introducing effective rear suspension: all these set a higher standard  -  but at a price. Never cheap, Vincents were (and remain) at the top of the price scale. Vincent's refusal to adopt "inferior" telescopic forks, when most other makers found them just fine, gave the machines a dated look. By 1955, high-performance parallel twins were encroaching on the Vincent's speed superiority, too. Perhaps this aversion to compromise, a lack of major innovation in the fifties and the always high price conspired to sink the company. But the mystique remains. And the price is still exclusive.