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Norton Commando Bearings

posted 25 Dec 2011, 05:07 by NOC NSW   [ updated 25 Dec 2011, 05:07 ]

Ordering bearings...

When you read "1 of 6203 17 X 40 X 12 Single Row Deep groove Ball" this means, that you need one bearing 6203, which is of the dimensions 17 X 40 X 12 and is a Single Row Deep groove Ball.

6203 is a universal number for this bearing size no matter what the brand. So you can ring up your local bearing place and say, "have you got a 6203", and be confident that it will fit, and that they will know what you are talking about.

If you want a sealed bearing this is the moment to add that info. Saying 2RS after the 6203 will get yo a bearing with a rubber shield on both sides, prepacked with grease.

While the size will remain constant the quality may differ. You will not go far wrong using the big names, NSK, FAG, SKF, RHP etc. All bearings are stock off the shelf sizes and should be available through any bearing distributer. When buying bearings get out the yellow pages and get prices from as many distributers as possible, also make sure you check with your Norton dealer as some of the more obscure sizes may be cheaper as a genuine spare part, because of the quantity used by Norton. It's up to you which bearing brands you use, but there is no or very little difference between top brands.

Front Wheel

1 of 6203 17 X 40 X 12 Single Row Deep groove Ball. You can use a sealed bearing. 
1 of 4203 17 X 40 X 16 Double Row Deep Groove Ball, sealed are rare.

Rear Wheel (true for post boltup and pre MKIII)

Wheel Hub

2 of  6203 17 X 40 X 12 Single Row Deep groove Ball, sealed if you want

Brake Drum

1 of 4203 17 X 40 X 16 Double Row Deep Groove Ball,  sealed are rare

Steering Head

2 of 6205, 25 X 52 X 15 Single Row Deep groove Ball, sealed.

Engine

Crankshaft

2 of NJ306E C3, 30 X 72 X 19 Cylindrical Roller Bearing, double lipped outer race, single lipped inner race, preferably brass caged, although polyamide cages are becoming more frequent. These are the so called 'Superblend' bearings. This bearing can be bought from any of the manufacturers (ie not just FAG) with a choice of cages ie. brass, steel, polymide.

Gearbox

Mainshaft

1 of RLS 5 2RS, 5/8 X 1 9/16 X 7/16 Deep Groove Ball, shielded, take the rubber shield out of the side facing inside the gearbox to allow gearbox oil flow (Note: not metric, imperial bearing size)

1 of RLS 9 2RS,  1 1/4 X 2 1/2 X 5/8 Deep Groove Ball, sealed, take the shield out of the side facing inside the gearbox to allow gearbox oil flow. (Note: Imperial bearing size)  Also, IMPORTANT;  the RLS 9 is listed in most catalogues as having a 1 & 1/8 bore, however get your dealer to have another look as they are also listed as having a 1 & 1/4 bore, which is what you need. They also sometimes bear the number 1654. Not every manufacturer will do them.  One manufacturer who does them is KSK. Another is RHP. This variant of the RLS 9 may have been commissioned just for Norton so availability will be relative.

Lay Shaft

The bikes were manufactured using; 1 of 6203 17 X 40 X 12 Single Row Deep groove Ball. This must be replaced by; 1 of NJ203, 17 X 40 X 12 (sometimes sold as a C3 clearance) Cylindrical Roller Bearing, double lipped outer race, single lipped inner race, you'll most likely get a polyamide cage from FAG, other materials available from other manufacturers. Polyamide cages are single use in this application as heating the box to remove them damages the polyamide.

Clutch

1 of 6007 Single Row Deep groove Ball, metal sealed, leave seals intact.

With the exception of the RLS 9 in the gearbox, all bearings are stock off the shelf sizes and should be available through any bearing distributer and will be made by any bearing manufacturer eg, NSK, FAG, SKF etc etc.

When buying bearings get out the yellow pages and get prices from as many distributers as possible, also make sure you check with your Norton dealer as some of the more obscure sizes (RLS9) may be cheaper as a genuine spare part, because of the quantity used by Norton. It's up to you which bearing brands you use, but there is no or very little difference between top brands.

This information supplied by:
Bob Davis, Hunter Valley Norton Owners Club