|
Make Model |
Norton Commando 750
Production Racer |
|
Year |
1972 |
|
Engine |
Air cooled, four stroke,
parallel twin cylinder, push rod 2
valves per cylinder. |
|
Capacity |
745 |
|
Bore x Stroke |
73 x 89 mm |
|
Compression Ratio |
|
|
Induction |
|
|
Ignition /
Starting |
|
|
Max Power |
|
|
Max Torque |
|
|
Transmission /
Drive |
4 Speed / chain |
|
Front Suspension |
|
|
Rear Suspension |
|
|
Front Brakes |
Single disc |
|
Rear Brakes |
178mm drum |
|
Front Tyre |
3.25-19 |
|
Rear Tyre |
4.00-18 |
|
Dry-Weight |
|
|
Fuel Capacity |
10 Litres |
|
Overview |
Motociclismo /
Motorcycle-USA |

The Life and Times of the Yellow Submarine
The Norton Commando Production Racer: More than a Café racer,
less than a GP bike.
When some wealthy collector finally builds the
ultimate motorcycle museum and designates one wing as the Hall of Influential
Motorcycles, it's not likely future visitors will see a Norton Commando
Production Racer there. By most of the accepted methods of the definition, the
bike simply wasn't that important, especially outside Great Britain. It began
life as a race-shop project, was launched as a marketing gimmick and, after a
brief spurt of dominance and popularity on the British and European racetracks,
went the way of other, suddenly uncompetitive racing machines. Which is to say,
into oblivion and numberless pieces.
And yet there exists reason to think otherwise of
the bike the British press instantly christened the "Yellow Submarine" on its
debut at the Racing and Sporting Motorcycle show in London in a freezing January
in 1971. The substance of the reason—bolstered by a healthy dose of 20/20
hindsight—is that the Commando Production Racer exists as one of, if not the
ultimate development of the motorcycle format the British were to stamp as
their own after World War II. This Production Racer a box-stock, genuine
factory-built device, not some "prodified" aftermarket machine could well be
considered the Ultimate British Vertical Twin.
Assuredly, there are Triumph Bon-nevilles being
sold as new even today. But even the most wide-eyed Bonnie fan will have to
admit that actual development of that machine stopped well before the workers'
co-op began building the bike in the mid-Seventies. Only Norton, of all the
British bike manufacturers, attempted to come to grips with the inherent
vibration of a big OHV vertical twin, and thus only Norton's Isolastic-framed
Commando, designed by Bob Trigg and launched in 1968, can be said to have
dragged the venerable old vertical twin into the postwar world. Thus by the
ineluctable process of logic, if the Commando street bike was the last word in
vertical twins from Britain, then the Production Racer was the exclamation point
at the end of the sentence. It was the fastest, best-handling, lightest and
quickest Commando you could buy.
A few performance figures from its era underscore
the last point dramatically. A stock Commando SS (a high-pipe version sold to
Americans looking for "street scrambler" machismo) consistently knocked off
12.6-second, 100-plus mph quarter-mile times in magazine tests of the day. And
when Tony Murphy took a '72 Production Racer to Willow Springs, former Norton
factory rep Brian Slark reports, he got the bike around in less than 1:40.
Considering that the lap record at the time the absolute lap record,
Slark further notes—was around 1:36, the motorcycle had to be taken very
seriously indeed as a racing machine.
In England, nobody had to be told. Built in
batches by Peter Inchley's famous "Long Shop" race department team (the name
comes from the long Nissen hut the shop called home, a building dating from the
time Thruxton Circuit was Thruxton Aerodrome, home to a B-17 bomber wing of the
Eighth Air Force), the Production
Racers were at first hard to come by. By late
1971, the Marketing Department at Norton had allocated enough to the race shop
to insure that any production-race grid in England would show at least a dozen
bikes and more often than not, that one of them would win the race. Some of this
was due to simple saturation—nobody else at the time built a race-ready
production racer for the class—but most of it was due to the quality of
Inchley's work.
To turn the street bike rolling-chassis that got
delivered from the Andover factory to the Long Shop into a Production Racer,
Inchley and development engineer factory racer Peter Williams had fine-tuned the
original Wally Wyatt project racer of 1969 considerably. Making use of the Long
Shop's proximity to the Thruxton circuit (as in: It's in the front yard, mate),
Williams and Inchley used run-it-and-see development as well as the tried and
true engine tweaks known to work on the old Atlas 750cc engine. The few bikes
that emerged from the Long Shop (estimates vary from less than 100 to less than
200 and documentation might as well be nonexistent) proved the worth of the
work, because in 1971, '72 and most of '73, they virtually owned their class in
England and Europe. Only the arrival of the Kawasaki Z-l and the curing of the
Honda CB750Kl's handling ills finally put them on their trailers.
The bike pictured here is typical of the breed.
Built in October 1971 and sold in January 1972, it incorporates most of the
midcourse corrections made to the Production Racer line. The frame, shocks,
swingarm and bottom half of the engine are standard Commando parts, but
everything else has the Long Shop stamp on it. First are the tires; Dunlop K81
TTlOOs were standard, but instead of the street bike's symmetrical 4.10x19s
front and rear, the racer got a 3.60 front section as a result of Thruxton
fiddling. The street's steel rims gave way to Akront WM3 40-spoke alloy wheels,
and the front drum of the Roadster was replaced by a Campagnolo-and-Lockheed
leading-caliper disc, the iron disc being bolted and splined to the front
alloy hub.
The fork valving was hand-worked using the stock
sliders and tubes, again based on racetrack experience. And the stock Isolastic
mounts were discarded in favor of new, less resilient mounts. A built-up alloy
head-steady replaced the soft stock item. Further chassis changes included the
obvious visual ones: the handmade alloy footpeg plates, the pegs themselves
(hand-turned, of course, out of solid aluminum), the exhaust pipe bracketry and
even the pipes, which were standard items hand-cut and rewelded to tuck in
tightly against the frame for cornering clearance. Only the class-required
equipment was left on the bike; speedo, tach, lights, horn, stoplight switch.
Not a single creature comfort unnecessary to winning races was left aboard.
The fiberglass fairing, five-gallon (U.S.) fuel
tank and solo-seat-cum-number-plates were designed in-house but built by local
industry; Mike Jackson, currently Sales Director of Andover Norton Ltd. believes
the pieces were made by Avon, only a few miles from the Andover factory.
Likewise, with the exception of the valve springs
(which came from S&W in America), the engine pieces were made either in Thruxton
or nearby. The head was alloy, gas-flowed and machined with no squish bands, a
configuration which, with the slightly domed forged pistons, gave a compression
ratio of 10.25:1. Together with the special phosphor bronze valve guides and
seats, the larger intake valves and large steel manifolds and 32mm Amal Racing
Concentric or remote-float GP "Matchbox" carbs, the package was good for 70 hp
at 7000 rpm. A Boyer electronic ignition kit was offered as an option, as was a
five-speed Rod Quaife gearbox, which had much closer ratios than the four-speed
racing unit that was standard.
By the time the Yellow Submarines made their
debut, many aftermarket manufacturers had already outfitted Commandos, of
course. The huge late-Sixties British Café racer market demanded it, even if the
real-racer contingent didn't. So there were quite a few Dunstall Commandos and
others to give the Submarines a run for their money. But the hours of Thruxton
testing paid off, and the factory product quickly earned a reputation as hard to
beat.
The genesis of this reputation wasn't merely the
lack of suitable competition. The traditional Commando qualities were elevated
to their highest pitch in the Submarine, and it was really those qualities that
set it on the trail to victory. Because of the engine's vast reservoir of
torque, the Commando pilot could dial his speed as though his twistgrip were a
rheostat. Further, the standard Commando's fundamental agility was sharpened by
the chassis tweaks of the Submarine until the bike was so stable and responsive
that it could be ridden anywhere on the track, whether on a long straight or
off-camber decreasing-radius turn. The generous (for the time) suspension travel
gave the Production Racer a soft ride almost unknown among racers of the day,
allowing the rider to concentrate on racing rather than just staying aboard. At
long tracks notably the Isle of Man—the fatigue-reducing aspects of the Commando
played a decisive role, for coupled to the plush suspension and superbly
comfortable riding position were the Isolastic engine mounts, which sopped up
virtually all the bad vibes the bike's vintage engine offered up. As a result of
this honing of the standard Commando's best characteristics, the word got to
Europe's (and even, to some extent, America's) street riders that the Commando
won its races not because it was hand-grenade quick or ridden by win-or-die
kamikaze pilots, but because it was somehow fundamentally different from all the
other Britbikes that had soldiered on with vertical twins in the past.
Which was, from the company's point of view, what
the whole exercise was all about. Confronting a swelling tide of Japanese "big
bikes," Norton's management tried to cover as many marketing bases as possible;
there were touring Commandos, "street-scrambler" Commandos and even the awful
and unlamented Hi-Rider, which was nothing more than a Commando Roadster with
ape-hanger handlebar and kicked-up seat, all led by a tiny headlight. But as the
Japanese took over more and more of the market, only the "sporting" aura clung
successfully to the Commando. And the factory sources we spoke with agreed that
the legend of the Commando's roadholding and sport-sense derived directly from
the Production Racer's brief dominance on the racetrack.
Considering that the Commando lived for seven
years, most of them in the face of ever-more exciting Japanese machinery, a new
BMW series, the all-new Ducati vee-twin 750s, the Laverda SFC and following Café
bikes in the face, in fact, of the biggest motorcycle explosion since WWII
the contribution of the racer might almost qualify it for inclusion in the Hall
of Influential Motorcycles. But only almost.
Had the Commando lived indeed, had Norton itself
lived as a major manufacturing concern of big-inch motorcycles a niche would be
certain for the Yellow Submarine. But since Norton, like BSA, Triumph and all
the rest of England's long-gone manufacturers eventually succumbed to
self-inflicted wounds, the Hall will not see a Commando Production Racer.
Instead, it will find its way into the garages of curio collectors, its epitaph
a simple one.
"Here rests the Norton Commando Production Racer.
Beautiful, fast, British— and too late." •