Norton Commando Technical Information
(This page does not work on mobile devices. Please review the tech data on an iPad or desktop.)
If you would like to see more resources for Norton Commando Technical information, head over to the Norton Commando Technical Resources at www.accessnorton.com
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. |
| .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 | |
Primary, Transmission & Rear Chain
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 |
| 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) |
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 (Kickstarter) 5/8 x9/16 x 7/16 in. | ||||
Layshaft (Clutch) 17mm x 40mm x 12mm | ||||
Carburetor & Air Filter
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. |
| 17ft.10 in. | |
Center of Gravity | 19 3/4 in. |
Seat Height | 33 1/2 in. |
Forks & 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. |
| 126 lb. per in. (depends on adjustment) | |
Fitted Length | 8.4 in. |
Total Length | 13 in. |
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. |
Drum Internal Diameter (New) | 7.007/ 6.997 in. |
Brake lining area Total | 13.6 Sq.in. |
Electircal
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 |
| 12V 6 Watt Bayonet | |
Direction Indicators | 12V 21 Watt |
Warning Lights | 12V 2 Watt |
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. |
| 1 ft./lb. | |
Oil pressure release valve | 25 ft./lb. |
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 |