I'm about to order some steering head bearings suitable for A, B and M Series BSAs. This set converts from the cup and cone set up of the originals to sealed ball bearings that require no further adjustment after fitting.
Price will be £42 plus postage and packing...Let me know if you need any...Ian
email (option): ian@wright52.plus.com
Hi Stuart...Mail sent...Ian
email (option): ian@wright52.plus.com
I can't tell you that Peter as I am not familiar with pre war models. You need to speak to Leon about that..However, going by the 1936 G14 I used to have I would say not...that was completely different....Ian
email (option): ian@wright52.plus.com
This type of bearing was original equipment on Norton Commandos and more recently Buells...others as well I would think....Ian
email (option): ian@wright52.plus.com
The spacer tube isn't required on an M20 as long as assembly instructions are followed...Ian
email (option): ian@wright52.plus.com
I believe Ian is correct in saying a spacer is not required BUT I make the following statement with the Caveat that I am not aware of which bearing is used in this kit but a deep groove single row ball bearing with the boundary dimensions of the head stem of the M20 should be able to comfortably take an axial load of 50% of the permissible static load recommended by the bearing Manufacturer a SKF bearing of this size would have typical Co (Static load )value of 11.2 Kn so it should be comfortable with the Axial loads imparted by the Geriatric M20 unless the hamfisted amongst us tightens the head stem nut with a 36" Pipe wrench
email (option): Grumpy.moran@gmail.com
That is quite correct Ron, these bearings are designed to take some axial load...However, there is no way in the home workshop of calculating what load is being applied, so the fitting instructions are written to avoid exerting such forces on the bearings during fitting...
Th best solution would be the fitting of a sleeve to prevent accidental excessive loading but not only would this add component cost to the bearing kit but also additional postage costs.
As with most things the market is sensitive to price and the (modified) bearings can be supplied currently for a similar price to a pattern cup and cone set so are a good upgrade at minimal (if any) extra cost...
If fitted in line with the instructions,the possibility of high axial loadings of the bearings will not be an issue...
If the suggestion was made in the instructions that a degree of axial loading was acceptable and keeping in mind most people can't measure that load, then inevitably, some bearings would be overloaded at fitting....Ian
email (option): ian@wright52.plus.com
Ian
Recieved A message from She who thinks she must be obeyed the Head stem Bearings Arrived This Day looks like I am in for a Busy time in the Man Cave When I get Home having picked up the new Carby on the way to the TT.
Cheers From the Jewel in the Irish Sea
Ron FTLDU
email (option): grump.moran@gmail.com
Hi
My steering head bearings feel like there is a notch in them. I can only feel this when the bike is off the stand and I'm paddling in and out of parking spaces and the like. It's as I move either side through approximately the straight ahead position. This isn't evident when on the rear stand, I guess that maybe how the load applies between rear up / down explains this? Anyway I'll need to do some investigations and repairs. Seeing this thread I want to check a few things about conversion as that seems like a sensible step as part of the work, even if I find some other cause:
1) The conversion bearings are modified in some way so I can't just buy the relevant bearings here in Singapore? Is the modification something I could get a local engineering firm to do?
2) looking at the post dates I guess I've missed the boat for getting a set via Ian, but Google found these, does anyone know if they're ok?
http://www.feked.com/bsa-a-b-and-m-models-steering-race-ball-end-conversion-kit.html
While I'm doing the work any recommendations, such as checking out the forks or other front end refurb that's just going to make more sense as part of the package?
Thanks
Richard 
email (option): Dickie.bobbie@hotmail.co.uk
Hi
Fixed it, or at least found the cause and addressed that, will see if it repeats. The lower fork link nearest the steering head was very slightly loose, so when I turned the handlebars from left to right I got a notch or rather a knock that felt just like a notch in the bearings. I've tightened this up, but unlike the top links this doesn't seem to thread and then have an offside nut for lockng, so perhaps something more is wrong, only time will tell!
Richard
email (option): dickie.bobbie@hotmail.co.uk
Richard your off side links should all be threaded and the long through bolts should have lock nuts. If you have a stripped thread in a link, you could do a temporary fix by using a nut with loctite (Clean the threads first with thinners or something). Then tighten to the desired adjustment and the Loctite will set and keep the nut in place.
Also check the old chestnut of having your front tank bolts too long that they will touch the steering stem......Ask me how I know this
Ron
email (option): ronpier@talk21.com