Norton Commando
| Norton | |
|---|---|
|
|
| 850 Commando (1973) | |
| Manufacturer |
Norton-Villiers from 1972: Norton Villiers Triumph (NVT) |
| Production period | 1967 to 1977 |
| class | motorcycle |
| design type | Naked bike , sports tourer |
| Motor data | |
| air-cooled two-cylinder four-stroke engine ( OHV ) | |
| Displacement (cm³) | 828 |
| Power (kW / PS ) | 37.5 / 51 at 6,250 rpm |
| Torque ( N m ) | 72.6 at 3,400 rpm |
| Top speed ( km / h) | 191 (test value) |
| transmission | 4-speed |
| drive | Roller chain 5/8 "× 3/8" |
| Brakes | front: a disc (Ø 270 mm) rear: drum (Ø 175 mm) |
| Wheelbase (mm) | 1,440 |
| Dimensions (L × W × H, mm): | 2,210 × 650 × 1110 |
| Seat height (cm) | 78 |
| Empty weight (kg) | 190 kg (dry) |
| Previous model | Norton Atlas |
The Norton Commando is a motorcycle with an air-cooled two - cylinder four-stroke engine made by the English manufacturer Norton-Villiers Ltd from Andover (Hampshire) (from 1972: Norton Villiers Triumph (NVT)). Initially offered as the Norton Commando 750 with a 749 cm³ engine, the displacement of the Commando 850 presented in the spring of 1973 was increased to 828 cm³.
The patented "Isolastic" frame is unique and no longer has anything in common with the "feather bed" frame previously used by Norton for many years. It is a central tubular frame with closed beams; The engine, transmission and rear swing arm are suspended in this main frame via a subframe with vibration-damping rubber elements. The framework was under the direction of the German atomic physicist Dr. Stephan Bauer has been completely redesigned by the Norton development team.
The first chassis had severe problems with frequent frame breaks on the top tube, these could be stopped by introducing an additional stiffening tube below the central tube.
In order to save production costs, the Commando frame was initially not manufactured by the long-standing supplier of the Featherbed chassis, Reynolds , but the order was placed with the Italian manufacturer Verlicchi. At that time, Verlicchi also manufactured the frames for Ducati motorcycles and was therefore a well-known address. However, the manufacturing quality of the frames manufactured by Verlicchi was so poor that all frames supplied had to be reworked by Reynolds. According to Ken Sprayson, engineer responsible for the manufacture of the featherbed chassis, Reynolds earned more from this rework than from the manufacture of a featherbed frame. Ultimately, after a while, the production of the Commando frames was relocated from Verlicchi to Reynolds.
The Commando engine was based on that of the Norton Atlas 750. In order to achieve a lower center of gravity and give the machine a more modern look, the engine was installed in the frame at an angle to the front. Since the Isolastic transmitted fewer vibrations from the engine to the frame and thus to the driver, the engines were subjected to much greater demands than in the comparatively much stronger vibrating predecessor models Norton Dominator 650 SS, Mercury or Atlas. In the early days, this led to numerous engine damage, as the crankshaft bearings were not able to withstand the high loads. In addition, the centrifugal adjusters of the Lucas ignition system wore out very quickly, the timing chains elongated disproportionately and in combination these factors led to a very high load on the crankshaft bearings, because the power output of the engine changed so disadvantageously that it was only satisfactory at very high speeds Performance. The engine variant "750 Combat" with a sharper camshaft and the resulting increased stress on the timing chain particularly stood out in this regard. Norton reacted by making numerous design changes to the crankcase, the crankshaft bearings and the crankshaft itself. However, these deficiencies could only be finally remedied with the 850 Mk2A and 850 MkIII model series with a stiffer crankshaft, stiffened crankcase in the area of the main bearing seats and, above all , spherical roller bearings obtained from the supplier FAG (with barrel-shaped rollers) as the main crankshaft bearing that could withstand bending vibrations of the crankshaft without defects.
Technology Commando 750 (850)
- transversely installed two-cylinder in- line engine (synchronous parallel twin ), 56 DIN PS (41 kW) at 6,750 / min (Commando 850 from 1973: 51 PS (37 kW) at 6,250 / min)
- 749 cm³ (828 cm³) displacement , a chain-driven camshaft,
2 overhead valves per cylinder operated by push rods and rocker arms - early 750: one drum brake each at the front and rear (Ø 175 mm; front as a duplex brake ). Brake pedal on the left.
- late 750, all 850 up to Mk2A: a hydraulically operated disc brake at the front (Ø 270 mm) with pliers behind the fork leg , drum brake at the rear (Ø 175 mm). Brake pedal on the left.
- all 850 MkIII have a hydraulically operated disc brake at the front with pliers in front of the fork leg and at the rear (Ø 270 mm). Brake pedal on the right.
- 2 Amal Concentric carburettors Ø 30 mm (early 750) or Ø 32 mm (750 Combat, late 750, all Commando 850). All 750 and 850 up to Mk2 with paper air filter in metal housing, from 850 Mk2A with foam air filter and noise-absorbing air filter housing made of plastic.
- Central tubular frame with closed beams, subframe for mounting the engine, gearbox and swing arm bearing
- Kick-starter , an additional 850 MkIII electric starter
- Primary drive via triplex roller chain. Tensioning the chain on all 750 and on 850 to Mk2A by moving the gearbox in the subframe, on 850 MkIII by hydraulic tensioning device
- 4-speed gearbox, rear-wheel drive via single roller chain 5/8 "× 3/8". Shift on the right on all 750 and on 850 to Mk2A, on the left on 850 MkIII
- 2-in-2 exhaust system in numerous different designs. Initially construction as a pure low-pass filter without an actual silencer ("straight through"), from 850 Mk2A with a damper insert ("black cap", "bean can"). All 750 without interference pipe between the exhaust manifolds, all 850 with interference pipe in front of the cylinder head
- Top speed : 180 km / h (185 km / h), in the test by MOTORRAD magazine, an 850 Mk2 ran 198.2 km / h.
- Acceleration : 0-100 km / h in 4.8 s (test value Commando 850)
Trivia
In the film One Week - The Adventure of a Lifetime , the leading actor traverses Canada on a Norton Commando 850 Bj. 1973, after having received news that he has cancer and that his chances of survival are slim.
literature
- The motorcycle : "The last islander", 10,000 km test Norton Commando 850 Interstate, issue 3/74 from February 9, 1974, Motor-Presse-Verlag Stuttgart
Web links
- Representation Isolastic frame (English)