Jekyll & Hyde: Norman Hyde Creates a Monster Bonneville

Half a century ago, Triumph's Bonneville became a byword for perform-ance, representing the epitome of British twin-cylinder engineering: fast, rakish, sweet-handling and stylish.

These days, John Bloor's born-again Bonnie has just clocked up its 10th birthday, but the are-born Triumph has yet to deliver a sharp-handling power-up derivative. That's all right, though: Norman Hyde has done it for them. Again. Hyde previously developed the parts needed to transform the stock Triumph Thruxton 900 into the Hyde Bonneville TX '60s-style café racer. He also created the Hyde Bonneville SS street scrambler, evoking the California cool of the classic-era TR6C street-enduro. Now Hyde has teamed up with Harris Performance, Britain's leading practitioners of the black art of frame design, to create the new-generation Hyde Harrier as the third in his trio of Hinckley Bonneville-based bikes.

The bike-building gospel according to St. Norman entails a successful blend of the old and new testaments. Indeed, with Öhlins suspension, AP Racing radial brakes, forged-aluminum Dymag wheels and serious attitude, the tube-framed, twin-shock Harrier is in every way a 21st century take on a '60s format, complete with lean, minimalist styling that's so yesterday once more.

Norman Hyde needs no introduction to dedicated Triumph enthusiasts around the world. His weekends were spent drag racing on a succession of ever more fearsome supercharged and/or twin-engined Triumphs of awesome performance and unlikely cubic capacity, all of which he created himself with the aid of accumulated factory knowledge.

Opening his own go-faster speed shop in '76, Norman Hyde Ltd.'s catalog at first bristled with parts aimed at improving the performance, handling and reliability of classic-era Triumph/BSA twins and triples, and Norton Commando twins. Then, to supplement this, in the '90s Hyde began developing a wide range of components for the modern Hinckley-built Triumph triples, to which he's now added parts for the Bonneville twins.

"Last year was the 21st birthday of our Harrier frame kit for the classic Triumphs, but it was also the 50th anniversary of the start of Bonneville production," Hyde says. "So I decided to ask the Harris brothers to help us produce a kind of jubilee edition that would let our customers start using the considerable extra performance that's locked up in the Hinckley Bonneville motor. It's a real blend of old and new, which I think the Harris boys got dead right. I hope our customers agree!"

Designed to utilize any pre-EFI Bonneville built between 2000 and 2007 as a donor bike, the basic Harrier kit (which sells for approximately $6300 at current exchange rates) consists of a Harris chromoly tubular-steel frame and swingarm, a 4.2-gallon aluminum fuel tank shaped to recall the Rob North works racers of the '70s, a seat unit, taillight, rear fender, rearsets, engine plates, battery box and sidestand. Besides the engine, this means the only major items retained from the donor Bonnie are the headlight, instruments, suspension, wheels, oil cooler and exhaust system. But Norman will also build one for you. If you ask nicely. And can pay.

The Hyde Harrier boasts a substantial power increase compared to stock, with 83 bhp now produced at the rear wheel at 7200 rpm, and 42 lb.-ft. of torque delivered at just 3000 revs. This comes courtesy of the revised engine package Hyde has concocted by boring the DOHC parallel-twin motor, as well as the beautifully made, freer-flowing and decidedly rortier-sounding twin-silencer stainless-steel pipe manufactured by Richard Bushell's Urbane Exhausts.

The tuned engine's displacement hike from 790 to 902cc is alone a worthwhile performance upgrade, even without the optimized carburetion obtained by fitting a pair of 35mm Keihin CR smoothbore carbs, matched to a ported and gas-flowed cylinder head carrying 2mm larger stainless valves fitted with stronger springs, and operated via special camshafts offering increased lift and longer duration. That extra performance is fed through the stock Bonneville five-speed transmission, but with a beefed-up oil-bath clutch with heavier springs and smaller Surflex aluminum plates that offer a higher clamp load.

Spending a couple days riding the Harrier along the Warwickshire highways and country lanes underlined just how successfully this bike captures the spirit of yesteryear in a modern context. It feels lighter and better balanced than the stock Bonneville. Sling a leg over the low, 30.5-inch-high seat and you find a close-coupled but surprisingly comfortable stance with pulled-back clip-ons that don't put undue weight on your shoulders. High footpegs and the upswept mufflers under your heels encourage you to ride in the classic style, parking your posterior on the hard padded seat and leaning with the bike as you hustle it round turns.

Do that, and surprise yourself with the amount of cornering speed you can carry. The Öhlins forks eats up rough roads and glues the quite grippy Avon Viper front tire to the tarmac. The Harris frame delivers a great sense of confidence, shrugging off the bumps on Britain's frostbitten, recession-ravaged roads, especially when cranked hard over in a fast fourth- or fifth-gear turn. No shaking of the bars in your hands, no speed wobbles, just planted.

There's noticeable extra zest all through the rev range on the Harrier compared to other Triumph twins, even Hyde-tuned ones. Get back on the gas exiting a turn and pickup is clean and precise. With 85 percent of peak torque already on tap at 2000 rpm, the Harrier will pull hard and strong practically off idle, with a sweet spot between 3000 and 6000 rpm you'll find yourself operating in most of the time. The spread of power and torque is so wide, you don't end up using the gearbox nearly as much as you might expect, and although you can feel power building in totally linear mode all the way to the 8000-rpm limiter, there's no excuse to ever flutter that. The forgiving nature of the meaty engine performance just asks you to short-shift at around 7000 rpm.

The very conservative steering geometry of the Harris chassis means that the Harrier is stable rather than quick-steering, but not so much you expend undue effort to make it change direction. It's in its element swinging easily from side to side along winding country roads, as you weight the footrests to change direction with that lovely, torquey motor lazily turning over just halfway to redline as it punches you out of turns with decisive urge. The Harrier's potent-yet-practical tuned Bonneville engine has enough punch to satisfy, but not so much you have to worry about preventing high-sides or hooking up the rear wheel. It's a great real-world ride.

The Hyde Harrier recreates one of the most distinctive, traditional Brit-bike themes, but in a 21st century idiom: the single-seat café racer. It's important to be able to see the engine, but you need the practicality and looks of a half-fairing, even if the Harrier's screen is too far back to easily tuck away behind down the straights. Get out the bandsaw, guys!

Dave Degens and the Triton ton-up Teds invented the café racer concept in the '60s; people like Paul Dunstall and Colin Seeley refined it; and Triumph, Norton and BSA all productionized it long before it was hijacked by the Italian mob in the '70s, or became the retro rage it is today. "You must remember that the original Thruxton Bonneville was the Honda Fireblade [CBR1000RR] of its day," Hyde proclaims. "It appealed to young lads who wanted the fastest, sexiest, most desirable bike around. The aim of the Hyde Harrier is to create a modern reference to that era, combining current technology and hassle-free reliability with improved performance and evocative styling."

Job done, I'd say.

With a 57.5-inch wheelbase, 26.5 degrees of rake and 4.3-4.6 inches of adjustable trail, the super-stable Harrier doesn't really need a steering damper. But if the damper fits, wear it!
Hyde's engine work yields a marked improvement in peak horsepower and torque. Bore is increased by 6mm via Wiseco pistons, which deliver a higher 10.5:1 compression ratio.
Each 451cc cylinder is fed by an oversized Keihin carb that blends old-school looks with new-school metering circuitry. When you're seeking power, velocity stacks are the way to go.
AP Racing radial calipers clamp 320mm Brembo discs, actuated by a master cylinder that's fully adjustable for span and leverage ratio. Öhlins FG324 fork would fit right in on an SBK grid.
Upswept stainless-steel mufflers carry the Harris label but are made by Urbane Exhausts. Forged-aluminum Dymag wheels pivot on a kit swingarm controlled by twin Öhlins shocks.
Britain's leading Triumph aftermarket specialist Norman Hyde spent over a decade working for the factory as a developmental engineer in the '70s and has been building and tuning Brit-bikes ever since.