General specifications for the ES2

1950-1953 with plunger suspension and the 1954 with swing arm suspension

Spare parts

Most parts are available from sites in the Links page and our online store BMH Trading - Classic Parts

Steering head bearing races

The races come as a set but they are not all identical. top one has a larger inner diameter to accommodate the collar of the locking nut. The bottom race is smaller but large enough to fit snugly over the flange built into the base of the steering head shaft. The other two races fit into the frame and have small holes to line up with the grease nipples inserted into the top and bottom shoulders of the steering head. Each race holds 17 x 5/16 " balls. this leaves enough room for movement without needing the balls to be packed in too tightly. The original races have a groove around the centre of the inner channel to allow for grease (and maybe metal to be pushed out of the track)?

Gasket sealant

Only use Permatex #3 or ThreeBond where oil is involved. Avoid the use of other sealants that may congeal or bead in the oilways.

Head gasket

Listed in the parts manual and was made of copper or aluminium. Lap the head to the cylinder instead for a tight fit. My 1950 motor has no gasket - this is the method recommended by a very experienced Norton mechanic.

Front wheel assembly

A schematic of the front wheel shows the placement of the spacers and bearings. On the side away from the brake drum a locking ring, felt washer and distance piece (with flat side to bearing) sit on the outside of the single row bearing. To assemble press single row bearing into place, followed by distance washer, felt washer and locking ring. Tighten ring. Insert distance small end first into hub. Make sure it is sitting firmly against the bearing just fitted. Enter double row bearing squarely into hub, pass front wheel spindle through until it enters opposite bearing. Drive on end of spindle until double row bearing comes up against the distance tube and stops. Fit pen steel washer (the very thin one), felt washer and larger steel washer and lightly peen the larger washer in position.


The following table gives the original part numbers and the modern equivalent.
Original part number
New number
Pen steel washer
26mm ID x 39.4mm OD x 0.3mm Thick OR 1.023 ID x 1.55 in OD x 0.011 in thick (1/64th)
Retaining washer
 28.58mm ID x 41.38mm OD x 1mm thich OR 1.125in ID x 1.625in OD x .039in thick (1/32nd)
Felt washers
Cut up an old hat. Approx 1/8 inch thick . It is only to keep grease in and dirt out.
Brake tab washers
I have had these off so many times I now make my own from thin tin plate. They are there only to stop the bolt from unscrewing.

The pen steel washer, felt and brake tabs can be purchased over the counter at a Norton parts stockist. The bearings are a standard fitting that can be matched at any bearing supply shop.


The Smith's chronometric speedometer on my ES2s was a 85mph version. The type of speedo was different and depended on the destination market, but Norton also supplied anything the agent (end customer) requested.. The cable must turn clockwise to operate the speedo correctly. The trip meter will function even if the cable runs in reverse. The speedo drive must turn at the ratio of 2:1. The 1:1.25 drive is for the magnetic speedo. The drive must turn 1600 revolutions per mile therefore with an accurate drill at 800 rpm the speedo should register 30mph. A later model drive unit (with round shoulders and a brass ferrule on one end and a brass insert where the drive cable is screwed on) can be dismantled, the ferrule carefully driven out, the gears reversed and converted to run in the opposite direction.