38 Es2 wheel bearings ?

Hi Ian, I'm guessing but as you're asking "only 2 bearings?" you havn't had the hub apart at the time of your writing.

I've just overhauled my 35 hub (luckily the bearings were ok), and found 1x single and 1x double row bearing.

Take it apart and you wont need a parts list to tell you what you need. I've never seen a double row jobbie before, and was surprised at how inexpensive they are through the usual Norton outlets i.e. the club or RGM. Not only that, you'll have all the bearing details in your hand.

Havnt got a clue as to whether navigator bearings will fit.

Ah, I recall my last visit to bearing supplies - it's off a 1935 what?!! Ooooh we dont do much imperial stuff - dont know where you'll get one of them mate. Yes, I know you dont methinks.

all the best now

Martin

As far as I can tell..........the same wheel bearings were used for decades. Being fitted to both singles and twins up to the 1970s.

Attachments give parts numbers and bearing numbers. Both bearings can be obtained from big name suppliers or other online sources.

The bearing numbers most commonly mentioned are single row - 6203 17 x 40 x12

and double row - 4203. 17 x 40 x 16.

The single row 6203 bearing is available in a sealed form which makes it almost maintenance free. The 4203 can be obtained in a sealed form but this is rare and very expensive.

Attachments
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I get my bearings from Simply Bearings, they are excellent to deal with and super quick. https://simplybearings.co.uk/shop

If you buy sealed bearings donât forget to flip the seal off with a pick and repack with grease, thereâs never much in there.

dan

According to bearing manufacturers, the amount of grease is correct. When you think about it, all it needs to do is lubricate the cage as there's no rubbing other than that.

Apparently overfilling can cause churning and high pressures making the seals pop off (although in the case of wheel bearings that's probably unlikely....)

Hi all,

If you take off 1 seal from each bearing and fit the open side towards the middle of the hub and grease nipple it should 'tick all the boxes'.

Regards, Richard.

Ian, Iâve just been googling and see what you mean, although I have been doing it on and off for years in my trail bikes and the most common cause of wheel bearing failure is water and grit ingress, hence my addition of more grease. I always use good quality bearings and have not noticed any premature failure, but will desist and see if I notice any difference!!

Dan

In the maintenance books it generally says to clean the bearings thoroughly and then pack with grease. My understanding of the word 'pack' is to cram the bearing with grease. The same as I would pack a suitcase or box. ie......very little wasted space within. I do this as I believe that any excess grease will be squidged to one side of the bearing.

Now that can not easily happen inside a sealed bearing, in which case too much grease would be a hinderence to the race movement. Which is why they probably contain the minimum amount required to do a good job.

Around 20 years ago, you could actually purchase a complete set of sealed ball bearings for the early AMC Norton gearboxes. I was tempted but then bottled out of getting a set.

Recently I noted that sealed 6306 crankcase bearings are readily available to fit a Dominator Timing side. Like those for the gearbox, I liked the idea of fit and forget. But........could they stand the heat?

The 6xxx and 4xxx series are just two of the basic, standard metric bearing ranges that are used by most everyone for all manner of jobs. As common as....

Millions of them on eBay. Just be aware that they come in a range of quality grades and it is best to buy the better, branded makes for motorcycle use.

I think that our wheels are rotating at a relatively slow speed for bearings and the 'over packing with grease' is just not an issue at slow rotations.

It was to our great benefit that British manufacturers used imported metric bearings in the 1930's. Perhaps they were cheap, but I don't think that Britain had much of a track record as a bearing manufacturer.

Norm