Not Your Average Norton Commando
I first saw Dave Webster’s monocoque Norton Commando at the International Norton Owners’ Rally. Uniquely distinctive for its angular aluminum sheet frame-cum-bodywork, the only really recognizably Norton components were the 750 Commando motor and transmission. Since that time, the monocoque has undergone some transformation, a transplant or two, and much development, all intended to make it a quick, smooth and race-sharp streetfighter.
Webster knows about building and racing motorcycles. Once an AHRMA regular on Aermacchis, Bultacos and Ducatis, he’s also a former motorcycle shop manager and expert mechanic. Now retired, he’s turned his focus to fettling the monocoque.
Dave Webster’s machine bears little resemblance to the famous factory monocoque of 1973 and is built using completely different principles. Peter Williams’s design used two hollow spars (much like today’s sportbikes, but then made in stainless steel) from which the powertrain was suspended. Fuel was carried in the steel “frame,” pre-dating Buell by 30 years.
Williams is quoted as saying, “Don’t ask me why we didn’t use aluminum, but the truth is we didn’t know how back then.”
Webster, though, chose to fabricate his “frame” from flat alloy plates welded together to form a hollow backbone “box.” And while the dry weight of the JPN machine was roughly 360 pounds, Webster estimates the finished weight of his bike at not much more than 300. The top section, where a conventional gas tank would be, contains the fuel, and a separate integral compartment below it holds engine oil. The engine and transmission are carried on an abbreviated Commando powertrain cradle using three isolastic mounts. Webster has also allowed for the motor position to be adjustable to optimize weight distribution.
Equally “revolutionary” is the engine. The 850cc motor (the “750” decals date from an earlier iteration) has its big end journals at 90 degrees instead of next to each other, giving a 270/450-degree firing sequence—the same arrangement used by Triumph’s America, Speedmaster and Scrambler. The advantages are the virtual elimination of the severe primary vibration found in most parallel twins, at the expense of some power pulsing at low revs. It’s also easier on the crankshaft, which, in the big Norton, is known to “whip” at high revs.
Webster used a bolt-up assembly, the Commando’s crankshaft cheeks being re-drilled to suit the new layout. Into the motor went high compression pistons and a Johnson cam. The cylinder head has also been modified, but not during Webster’s ownership, so the precise details are unknown.
A pair of 35mm Mikuni flat slide racing carbs feed gas, lit by a conventional points ignition firing Dyna coils. The exhaust headers are Dunstall pattern, and Webster made the mufflers himself.
The rest of the machine is made up from parts that were in Webster’s garage. The inverted fork and triple trees came from a 1991 Suzuki GSX-R 750, while a Honda CBR600F2 donated the four piston Nissin calipers. Hubs and rotors are from Barnes. The choice of brakes was critical: modern calipers are designed to work with alloy wheels, not wire wheels, and the clearance between calipers and spokes required using the slim Nissin assemblies, which Webster attached to carriers he made himself. At the rear is a JMC swingarm fitted with Koni Dial-a-ride spring/shock units.
The special’s slightly rough-and-ready appearance belies its unique conception and construction. Webster’s aluminum welds are neat, every component works exactly as it should, and the attention to functional detail is impressive.
The racing carbs make the Norton Commando a reluctant cold starter, so Webster bump-starts the bike, the motor catching with a bark. The offset crank gives the exhaust a lop-sided throb, more Ducati than Norton, but the thrashing from the valvetrain is pure Commando. I’m tailing Webster and I’m surprised at how rapidly the Norton moves ahead when he cracks the throttle.
We pull over, and trade bikes.
THE MOTOR WANTS TO REV IN A WAY THAT’S UNLIKE ANY NORTON I’ve ridden before; the race-style, quarter-turn twistgrip contributes, I’m sure, and the crank must be way lighter than standard. I give the engine a handful of revs to get the bike rolling, and away.
Immediately, I know this is like no Commando I’ve ever ridden. I’m guessing the motor is making on the good side of 75 hp, and combined with the light weight, rev-happy engine and sharp handling it feels more Ducati Supersport than seventies Britbike.
The revs build with an unexpected rapidity and a generous thrust, and the motor gets smoother the faster it turns. This is easily the fastest Commando I’ve come across. And in spite of the isolastic mount system, which can cause some elasticity in a Commandos handling, all feels secure on the Webster machine. The handling is taut and precise with little steering effort—Webster seems to have hit the front-end geometric sweet spot between stability and flickability.
Most of all, though, it’s just a blast to ride, especially with the soundtrack, which comes in with a howl from the intakes and a growl from the exhaust when you wind open the throttle. Dave Webster has created a remarkable and unconventional special, a worthy successor to Peter Williams’s JPS monocoque Norton Commando of 1973.
Norton Commando and The Original Monocoque
By 1972, the Commando, with 78 hp at best, was struggling against competing two-stroke Suzukis and Yamahas in production and endurance racing. Rider and team engineer Peter Williams decided to focus on weight reduction, handling and aerodynamics—just as Joe Craig had done at Norton in the fifties.
For 1973, Williams and the JPN team developed the hollow “monocoque” frame, reducing frontal area while improving rigidity and trimming weight. A new fairing was developed in the wind tunnel of Britain’s Motor Industry Research Association.
The final monocoque design allowed the overall height of the bike to be reduced by six inches at the windshield, resulting in a drag coefficient of just 0.22—a truly impressive number. Williams himself rode the Norton monocoque to victory in the 1973 Isle of Man Production TT.
by Robert Smith Canadian Biker #247
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