Steering head bearings

[Nomad54]

I am in the process of rebuilding my a10  ex police model. I want to put taper roller bearings in the steering head. Can anyone give me the correct bearing numbers as I believe the top and bottom are different sizes. I know SRM supply bearings but there is no info on the sizes.

[jhg1958]

I am probably wrong but I would have thought there would be no part number for the roller bearings as they are an after market improvement. If you ring Burton Bike Bits they will direct you to the right bearings. I have always found them very knowledgeable and helpful (other suppliers are available).

I put them on mine. I found that the roller bearings lifted the top yolk a few mm. Not a problem until I replaced the nacel. The slight change caused me no end of headaches. It might have been the bearing I bought or more likely my fitting them.

If I was do it an again I would but ball bearings in.
John

[limeyrob]

Some upgrades make sense but I'm not sure the headstock rollers are one. My A10 is close to 60 years old (as are most) and there's virtually no wear.  I've seen corroded races where they have not been kept greased and water has got in but they seem well up to the job.  I have gone for sealed wheel bearings as keeping them greased while not getting grease in the brakes is a bit of a faff.

[JulianS]

The bearings used in the conversion are machined to fit the bike, not off the shelf from a bearing supplier.

[Topdad]

I bought mine from Goerge Prew off the shelf and have had no problems with them and that was 8 yrs ago.

[morris]

SKF 32006X will work but need to be modified. I did it because I was in a bit of a hurry and my bearings supplier had them on the shelf. It worked but there’s quite a lot of work involved to modify them. You’ll have to turn a ring for the inner race and skim the outer one. Not worth the hassle really because most parts dealers sell them ready made

[Slymo]

I've had to replace taper bearings in the headstocks of two BMWs one from 1975 and one from 1990 something. I also replaced the crowded row headstock bearing in my 58 A10. They do take a little bit more adjustment to get them right but it's way less faff than modifying for taper rollers and whilst my sample is very unscientifically small I reckon they last at least as long.

[Rex]

To me they always seem to be a mod that's apparently worth having (along with belt drives and electronic mags) but don't offer any real improvement or advantage over standard.
I've also had the problem over the years where the bearings "show" over and under the headstock as they're a different stack height to standard, and that ain't too good.

[limeyrob]

I'm not sure they are the same. A deep contact ball race and a taper roller do different jobs.  The balls can take loads in a wide range of directions and can allow for some flex and misalignment.  A taper roller is optimized for high radial loads but less so for axial whereas the ball and cup is very good on axial.  To me the taper roller conversion looks like a solution looking for a problem that's not there.

[vemmi]

I am in the process of rebuilding my a10  ex police model. I want to put taper roller bearings in the steering head. Can anyone give me the correct bearing numbers as I believe the top and bottom are different sizes. I know SRM supply bearings but there is no info on the sizes.

Did the SRM conversion. Yep top and bottom are different size and You'll should check which one goes to which side before using brutal force, because at least in my bike those fitted quite easily on the right side.