Norton Commando

The Norton Commando is a motorcycle with air-cooled two-cylinder four-stroke engine of the English manufacturer Norton Villiers Ltd.. from Andover ( Hampshire) (from 1972: Norton -Villiers - Triumph, NVT). Initially offered as a Norton Commando 750 with 749- cc engine, the engine capacity was increased in the 850 Commando presented in the spring of 1973 to 828 cm ³.

Unique is the patented " Isolastic " frame, which has nothing in common with the " featherbed " frame previously used Norton for many years. It is a central tube frame with closed stringers; Engine, transmission and rear swing arm are suspended via an auxiliary frame with vibration-damping rubber elements in the main frame. The frame was a complete redesign of the Norton - development team, led by the German nuclear physicist Dr. Stephan Bauer.

The first chassis had massive problems with frequent breaks in the frame top tube area, this could be turned off by the introduction of an additional stiffening tube below the central tube.

To save production costs, the Commando frame was not initially produced by the long-term supplier of the Featherbed chassis Reynolds, but awarded the contract to the Italian manufacturer Verlicchi. Verlicchi presented at this time forth the framework for Ducati motorcycles, was, therefore, quite prestigious address. However, the production quality of the frames produced at Verlicchi was so bad that all supplied frame had to be reworked at Reynolds. According to the authorities responsible for the production of the Featherbed chassis engineer Ken Sprayson Reynolds earned on these rework more than in the production of a Featherbed frame. Ultimately, the production of the Commando frame was therefore shifted again from Verlicchi to Reynolds back after some time.

The engine of the Commando was based on the Norton Atlas 750 To a lower center of gravity to achieve and provide the machine with a modern look, the engine was installed tilted forward in the frame. Since fewer vibrations from the engine to the frame, and thus the driver has been transmitted by the Isolastic, the engines were much more required than in the comparatively much more vibrant predecessors Norton Dominator 650 SS, Mercury or Atlas. This resulted in the initial period to numerous engine damage because the crankshaft bearing the required high stress were no match. In addition, the centrifugal governor of the Lucas ignition system worn very quickly, the timing chains längten be disproportionately and in combination, these factors to a very high load on the crankshaft bearings, because the output of the engine unvorteihaft so altered that it satisfactory only at very high speeds performance gave. The engine variant " 750 Combat" with sharper camshaft and the achievement of stronger again stress the timing chain did in this regard out particularly inglorious. Norton responded through numerous design changes of the crankcase, the crankshaft bearings and the crankshaft could be parked itself definitively these defects but only with the Model 850 Mk2A and 850 MkIII with a stiffer crankshaft, considerably stiffened crankcase at the main bearing seats and related mainly from supplier FAG could allow crankshaft main bearings with barrel-shaped rollers, so-called spherical roller bearings, the bending vibrations of the crankshaft without any defect.

Technology Commando 750 ( 850)

  • Transversely mounted two-cylinder in-line engine ( co-rotating parallel twin), 56 DIN hp at 6.750/min ( Commando 850 from 1973: 51 hp at 6.250/min )
  • 749 cm ³ (828 cm ³) displacement, OHV valve control, a chain-driven camshaft, Operated two valves per cylinder via pushrods and rocker arms
  • Early 750: one drum brakes front and rear ( Ø 175 mm front brake as a duplex ). Brake pedal on the left side.
  • Late 750, all 850 to Mk2A: a hydraulically actuated front disc brake (Ø 270 mm) with pliers behind the fork leg, rear drum brake ( Ø 175 mm). Brake pedal on the left side.
  • All 850 MkIII is a hydraulically actuated disc brake with forceps in front of the fork leg and rear ( 270 mm ). Brake pedal on the right side.
  • 2 Amal Concentric carburettor Ø 30 mm (early 750 ) or Ø 32 mm (750 Combat, late 750, all Commando 850). All 750 and 850 to S2 with paper air filter in a metal case, from 850 Mk2A with foam air filter and noise-absorbing air filter housing made ​​of plastic.
  • Central tube frame with closed joists, sub-frame for inclusion of engine, gearbox and swingarm bearings
  • Kickstarter, MkIII at 850 additional electric starter
  • Primary drive via triplex roller chain. Tension of the chain for all 750 and 850 to Mk2A by movement of the transmission in the subframe, at 850 MkIII by hydraulic tensioner
  • 4 -speed transmission, rear wheel drive via single roller chain 5/8 " x 3 /8". Circuit for all 750 and 850 to Mk2A right, at 850 MkIII left
  • 2 -into-2 exhaust system in many different versions. Initial construction as a pure low-pass filter without actual muffler ("straight through" ), from 850 Mk2A with Baffle ( "black hats", " bean can" ). All 750 without interference pipe between the exhaust manifolds, all 850 with interference tube in front of the cylinder head
  • Maximum speed: 180 km / h (185 km / h), in the test of the magazine MOTORCYCLE ran a 850 Mk2 198.2 km / h
  • Acceleration: 0-100 km / h in 4.8 s ( test value Commando 850)
Engine displacement Velocity Andover (Hampshire) Reynolds Cycle Technology Timing belt (camshaft) Straight-twin engine Kick start Starter (engine)
609575
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