Norton Commando Technical Data

Norton Commando Motorcycle Specs

Norton Commando Motorcycle Specs

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Norton Commando Technical Data Index

Engine
Primary Transmission And Rear Chain
Gearbox
Carburetor And Air Filter
Frame/ Isolastics
Forks/ Shocks
Brakes Wheels And Tires
Electrical
Torque Settings
Capacities

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Norton Commando Engine Specs

  750 850
Capacity
745cc (45 cu. in.) 828cc (50.5 cu. in.)
Bore
2.875 in. (73mm) 3.030 in. (77mm)
Stroke
3.503 in. (89mm) 3.503 in. (89mm)
Max. Torque(5000 rpm)
48 lb./ft. (Combat 49lb) 56 lb./ft. 
Compression Ratio
9:1 (Combat 10:1) 8.5:1
Maximum Speed
112 MPH (Standard) 122 MPH
Spark Plug
Champion N7Y or Equivalent.
Spark Plug Gap
.023 - .028 in.
Contact Breaker Gap
.014 - .016 in.
Ignition Timing
28 degrees BTDC (Fully Advanced)
Valve Clearances (Cold)
750 850
Inlet
.006 in. (Combat .008) .006 in.
Exhaust
.008 in. (Combat .010) .008 in.
Camshaft Chain Adj.
3/16 in. (4.8mm) play at top of chain.
Valve Seat Angles
45 degrees inlet and exhaust
 
Norton Commando Primary
Engine Sprocket
26 Teeth
Clutch Housing
57 Teeth
Primary Chain
Triple Row, 92 Pitches, .375in. x .250in.
Rear Chain
99 Pitches, .400in. x .380 in.
Clutch Pushrod Length
9.813/ 9.803 in. (244.250/ 243.996 mm)
Clutch Pushrod Diameter
.237/ .232 in. (6.019/ 5.892 mm)
Clutch Ball Bearing
1/2 in. (12.70) Diameter
Clutch Plates
4 fiber clutch, 5 metal clutch (Sintered Bronze)
Clutch Adjuster
1/2 in. x 20 UNF 2A
Clutch Adjuster Length
.904 in. x .894 in ( 22.962/ 22.708 mm)
 
Norton Commando Gearbox

Estimated Speeds Using 19-23 Tooth Gearbox Sprockets

Sprocket Size Overall Gear Ratio 6000 rpm 6500 rpm 7000 rpm
19 4.84 92 mph 99 mph 107 mph
20 4.60 97 mph 105 mph 113 mph
21 4.38 102 mph 110 mph 119 mph
22 4.18 106 mph 115 mph 121 mph
23 3.99 112 mph 121 mph 130 mph

( I recommend using a 20 or 21 tooth sprocket depending on where you live)

 

Number Of Teeth On Pinions

First Layshaft         28 teeth
Second Layshaft     24 teeth
Third Layshaft        20 teeth
Fourth Layshaft      14 teeth
First Mainshaft       14 teeth
Second Mainshaft   18 teeth
Third Mainshaft      21 teeth
Fourth Mainshaft    23 teeth

Ball Journal Bearings

Mainshaft (Clutch End)      11/4 x 21/2 x 5/8 in.
Mainshaft (Kickstarter)     5/8 x9/16 x 7/16 in.
Layshaft (Clutch)              17mm x 40mm x 12mm
 

Norton Cammando Carb

Standard 750 (Twin Amal 930 30mm) 

  Main Jet Needle Jet Needle Position Throttle Valve
1970 220,180, or 210 .107 Middle 3
1971 220 .106 Middle 3
1972 220 or 210 .106 Middle/ Top 3
Standard 850 (Twin Amal 932 32mm)

Main Jet

260
Needle Jet 106
Needle Position Top
Throttle Valve 31/2
Needle 928/104
Choke Tube 928/ 107
Air Filter Pleated impregnated paper

*Please note it is best to use Amal Mk 2 Carbs with a K&N Air Filter In My Opinion.

*It is best to use straight through 'Reverse Cone' after market exhausts with these settings

 

Norton Commando Frame Isolastics

Front Isolastic

Shim Thickness Available
.005, .010, .020, .030, in.
Free Play
.010 in.
Bolt
7.13 in., 1/2 in. x 20 UNF.
Buffer Quantity
2
Buffer Diameter
1 11/16 in.
Buffer Thickness
1/2 in.
Bush Quantity
2
Bush Thickness
5/8 in. tapered to .510 in.
Spacer
2.573/ 2.553

Rear Isolastic

Bolt Torque Setting
300 in./ lb.
Shim Thickness Available
.005, .010, .020, .030, in.
Free Play
.010 in.
Stud
13 in.
Stud Thread Size
1/2 in. x 20 UNF 2A
Buffer Quantity
2
Buffer Diameter
1 5/16 in.
Buffer Thickness
1/2 in.
Bush Quantity
3
Bush Thickness
1/2 in. tapered to .410 in.
Spacer
1.560 in./ 1.550 in.

Dimensions

Height
40.75 in.
Length
87.5 in.
Wheelbase
56.75 in.
Weight (Roadster)
420 lb
Weight (Interstate)
435 lb.
Width
26 in.
Turning Circle
17ft.10 in.
Center of Gravity
19 3/4 in.
Seat Height
33 1/2 in.
 
Norton Commando Forks and Shocks

Forks ( Telescopic with internal Springs Hydraulically damped)

Total Fork Travel
6 in.
Fork Leg Oil Capacity
150 cc in each leg
Springs
75 1/2 Coils 
  18.687 in. free length
  36.5 lb./ in

Shocks (Girling Oil filled with External Springs)

Spring Free Length
8.75 in.
Rate
126 lb. per in. (depends on adjustment)
Fitted Length
8.4 in.
Total Length
13 in.
 

Norton Commando Brakes Wheels Tires

Front Wheel

Rim Size
WM2 - 19 in.
L.H. Wheel Bearing
17x40x12 mm.
R.H. Wheel Bearing
NM 17721
Spindle
.66671/ 6670 in.
Tire Size
4.10 x 19 in.
Tire Pressure
26 PSI
Tire Diameter
26.46 in. (Dunlop)
Tire Width
4 in.

Front Brake (Disc)

Pad friction area
1.65 in.
Pad Thickness (New with Backing)
.38/ .37 in.
Pad Minimum Thickness
.0625 in.
Disc Diameter
10.70 in.
Disc Width
.260/ .250 in.
Brake Fluid
Lockheed 329 Quality

Front Brake (Drum)

Type
Twin Leading Shoe
Drum Diameter
8 in.
Brake lining area Total
18.69 Sq. in.

Rear Wheel

Rim Size
WM2 - 19in.
Wheel Bearings
17x40x12 mm
Sprocket Bearing
NM 177721
Tire Size
4.10x19in.
Tire Pressure
26 lbs./PSI
Tire Diameter
26.46 in.
Tire Width
4 in.

Rear Brake

Drum Internal Diameter (New)
7.007/ 6.997 in.
Brake lining area Total
13.6 Sq.in.
 

Norton Commando Electrical Lucas

General

Voltage
12 V Positive earth/ ground
Alternator
RM 21
Rectifier
2 DS 506
Zener Diode
Z D 715
Battery Rating
10 Amp Hour at !0 hour rate
Coil 
17 M6
Ballast Resistor
3 BR
Contact Breaker
6 CA or 10CA
Warning Light Assimilator
3 AW
Fuse
35 Amp.
Flasher Unit
8FL

Bulbs

Headlight
12 V 45/40 Watt
Tail/ Stop light
12V 21/ 6 Watt Offset
Parking
12V 6 Watt Bayonet
Direction Indicators
12V 21 Watt
Warning Lights
12V 2 Watt
 

Norton Commando Torque Settings

3/8 in. Cylinder head nuts & bolts
30 ft./lb.
5/16 in. Cylinder head bolts
20 ft./lb.
3/8 in. Cylinder base nuts
25 ft./lb.
5/16 in. Cylinder base nuts
20 ft. /lb.
Cylinder through bolt (850cc)
30 ft./lb.
Con rod nuts
25 ft./lb.
Rocker cover plate bolt
8 ft./lb.
Crankshaft nuts
25 ft./lb.
Cam Chain tensioner nuts
15 ft./lb.
Oil Pump stud nuts
15 ft./lb.
Rocker feed banjo bolts
15 ft./lb.
Engine mount bolts
25 ft./lb.
Rotor nut
80 ft./lb.
Alternator stud nuts
15 ft./lb.
Clutch to Mainshaft nut
70 ft./lb.
Mainshaft nut
40/50 ft./lb.
Counter shaft sprocket nut
80 ft./lb.
Gearbox inner cover nuts
12 ft./lb.
Top gearbox fixing bolts
55 ft./lb.
Rear shock nuts
30 ft./lb.
Isolastic bolts
25 ft./lb.
Fork Top nuts
30 ft./lb.
Fork Yoke Pinch bolts
30 ft. /lb.
Steering head main nut
30 ft./lb.
Disk Caliper mounting bolts
30 ft./lb.
Disk Caliper end plug
26 ft./lb.
Disc Mounting nuts
20 ft./lb.
Drum brake cam nuts
30 ft./lb.
Sidestand nut
50 ft./lb.
Zenor Diode nut
2 ft./lb.
Coil bracket nuts
1 ft./lb.
Oil pressure release valve
25 ft./lb.
 

Norton Commando Capacities

Engine oil tank
5 imp./ 6 US. Pints
Primary Chaincase
200 cc, 7 fl.oz.
Gearbox
.75 imp./ .9 US. Pints
Front Forks
150 cc, 5 fl.oz.
Interpol fuel tank
4 imp. gallons
Interpol fuel tank (radio)
3 1/2 imp.gallons
Interstate fuel tank
5 1/2 or 5 1/4 gallons
Hi Rider fuel tank
2 imp. gallons
Roadster fuel tank
2 1/4 or 2 1/2 gallons
Fastback fuel tank
3 1/4 or 4 gallons