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1973 Norton Commando

1973 Norton Commando

ABOVE: 1973 Norton Commando 750 Roadster was more or less the “standard” Commando.

After the dismal finish of the 1972 model year, thanks to the Combat engine, 1973 was a good year for Norton Motorcycles. The entire model line had benefited from the engine fixes developed to counter the Combat’s tendency to break pistons & eat main bearings. The new Superblend main bearings were now standard on all models. While the Combat engine continued to appear in the catalog briefly, it had been canceled in 1972 because the problems were just too great & Norton’s scarce resources needed to be directed into its mainstream line of engines.

When the 1973 Norton Commando lineup was announced, the Commando Fastback & Fastback LR had been dropped. The 1973 Norton Commando Roadster, Interstate & Hi-Rider continued on in MkV form, now with optional turn signals, which had only been listed for the first time as an option on the 1972 Norton Commando Interstate. All engines now had the 32mm Amal 932 Concentric carbs & intake tracts from the Combat engine, but with reduced compression ratio & higher gearing. Only the Hi-Rider soldiered on with the old 8-inch TLS front brake, all others now had a single front disk brake on the right & the old drum out back.

ABOVE: The 1973 Norton Commando Interstate was the long-range touring edition.

The biggest news for the 1973 Norton Commando was the new 850 Commando line. Yes, the ancient 1948 Bert Hopwood design that started life as at 500cc, had one final growth spurt, this time to 829cc, to be called the 850 Commando. This was accomplished by boring the cylinders out to 77mm & retaining the 89mm stroke. The compression ratio was lowered to 8.5:1. Power output was advertised as 60hp at a leisurely 6,200rpm, but was probably more like 53hp, pretty much the same as the 750. The difference was that the 850 got it done with much less stress, at a lower rpm & was thus smoother & more reliable. Prolonged cruising at 5800rpm was possible & this calculated out to about 100mph in top gear. A redesigned cylinder block now had through bolts from head to crankcase as well as short studs & nuts. Flywheel weight was adjusted to compensate for the heavier pistons. An all metal clutch & reinforced gearbox casing were added. A cross-over pipe now joined the two exhaust pipes just downstream from the heads.

750 & 850 ONE YEAR ONLY
The 750 & 850 were both produced throughout most of 1973 & were available in all models. In October 1973, the last 750 rolled off the assembly line. Well, that’s not exactly correct. Because a new short-stroke 750 was briefly offered as an option on the John Player Norton & the Commando Roadster. By shortening the stroke to 80.4mm while retaining the 77mm bore from the 850, the new displacement was 749cc (the old 750 was actually 745cc), with a less undersquare engine geometry. This engine was an offshoot from the works experience Norton gained in production racing.

The hot new John Player Norton took the Norton Commando Production Racer & did it one better. Its stunning red, white & blue paint scheme & unique classic cafe-style fairing, tank, seat & tail section made this one of the most eye-catching motorcycles of all time. It came standard with low clip-on handlebars & rearset footpegs & foot controls. The fairing had 2 side-by-side headlights flared in, along with standard turn signals.

By 1973, Norton Motorcycles looked like the strongest, most viable of the British Motorcycle Manufacturers. Once might BSA & Triumph had sustained huge losses & suffered from horrendous management & were on the verge of collapse. In July 1973, Norton’s parent-company, Manganese Bronze Holdings, with help from Britain’s Department of Trade & Industry, bought the beleaguered BSA & Triumph and formed a new company called “Norton Villiers Triumph”, or NVT. With it came a new plan: Close Triumph’s legendary Meriden factory & move all Triumph production into Norton’s Wolverhampton plant. When the Triumph workers got wind of this, they immediately took over the Meriden facility & held it for 18 months, halting all Triumph twin production throughout most of 1974 & all of 1975. This on top of all the other problems Norton was facing at the time was simply more than they could handle.

1973 Norton Commando SPECIFICATIOS

Model designations:







Engine type

Displacement 750

Displacement 850

”  Short-Stroke 750

Bore & Stroke 750

Bore & Stroke 850

B & S Short-Stroke 750




Engine output

Oil system

Oil capacity

Primary drive



Ratios, overall:

1st, bottom



4th, top

Final drive

Frame type

Suspension, front

Suspension, rear

Brake, front

Brake, rear


Seat height





Production Racer



Air-cooled OHV parallel twin

746cc / 45 ci



73mm X 89mm / 2.875″ X 3.503″

77mm X 89mm / 3.03″ X 3.503″

77mm X 80.4mm / 3.03″ X 3.17″


2- Amal Concentric, 32mm

Battery & coil, Lucas

60 bhp @ 6200 rpm

Dry sump

6 pts

Triplex chain

Multi-plate diaphragm, wet

4-speed constant-mesh, right-foot shift







Welded double cradle, Isolastic Suspension

Telescopic fork, hydraulic damping

Swing Arm, 2 dampers, Isolastic mounts

10″ disk, 2-piston hydraulic caliper

7″ SLS drum, full width



430 lbs