The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: LJ. on 06.07. 2007 18:38

Title: Steering Head Bearings!
Post by: LJ. on 06.07. 2007 18:38

Hurrah! At last I have got the job done... One of them jobs that have been waiting to be done for such a long time. The bearings were so bad that the castle nut could no longer be done up and riding two up was getting very wobbly, so I got some new parts and made a go for it. (Costing nearly £100 for complete set plus castle nut and chrome top nut) I was a bit nervous as I had not done anything like this before. I found it to be real easy, although made it a bit awkward by leaving the headlamp nacelle and all wiring intact, but with plenty of string and hooks in the ceiling all was well suspended!  *eek*

As soon as I was done it was straight out for a test run, this was gone midnight! What an improvement! All that is left is some fine adjustments that will be ironed out over the next few dry days (I hope!) and she'll be a good un!

I did take the oppotunity to drill and insert a greasing nipple on the left side of the head, I didnt think about the gap between the cylinder part and the wrap round covering if you know what I mean. All that is needed is a longer threaded end to the nipple and all should be well.

I did opt for the ball and cups rather than taper roller bearings. I had heard of there being problems with having to machine out for them to fit.

Has anyone else had a crack at fitting steering bearings?
Title: Re: Steering Head Bearings!
Post by: G/F DAVE on 06.07. 2007 20:23
Hi, L J  I have fitted taper bearing kits to two of my machines, I have a 58 super rocket  fitted with (TRIUMPH PRE-UNIT MOTOR) this is fitted with a SRM kit easy to fit and a worthwhile improvement, on my 52 A10 I copied SRM bearing measurements and made up my own, had to sleeve top inner bearing & grind a radius on both top & bottom outer bearing cases, I also have two M20.s one civilian, and one WM20 ,these are great machines easy to work on & easy to obtain spares,   but not if you are in a hurry though!!  best take your A10 regards DAVE,,,,,
Title: Re: Steering Head Bearings!
Post by: dpaddock on 08.07. 2007 02:45
I suppose there are many adherents to both of the bearing styles. For me, I prefer the factory style ball and cup for road riding. For scrambles, road racing and other heavy duty riding I suppose the taper roller is better.
But grease fittings seem superfluous; if they were necessary, I believe BSA would have fitted them and made note in the Maintenance Manual.
Title: Re: Steering Head Bearings!
Post by: LJ. on 08.07. 2007 08:55
if they were necessary, I believe BSA would have fitted them and made note in the Maintenance Manual.

They did! at least with my M21 they did, the greasing points (nipples) are all over the place, so why not on the later A10. Is there any on the very early A7 & A10s?

I wonder if it was the start of cost cutting and general downward spireling in quality of materials etc that eventually led to the closing of BSA?
Title: Re: Steering Head Bearings!
Post by: bsa-bill on 08.07. 2007 09:17
grease nipple on my 61 A10 is on the headstock about an inch below the top bearing and same on my 58 project,
Suppose the idea was to fill the headstock tube with grease until it reached the bearings.
Bit over the top though

All the best - Bill
Title: Re: Steering Head Bearings!
Post by: dpaddock on 08.07. 2007 21:47
You're absolutely right - the grease nipples ARE fitted. Sorry.
But why would one want to FILL the headstock with grease? And, for that matter, the wheel hubs? I don't understand BSA's reasoning re this.
Title: Re: Steering Head Bearings!
Post by: bsa-bill on 08.07. 2007 22:07
well the original design was maybe before the days of sealed bearings ( not sure when they came in ) pumping grease into the headstock until it emerged from the bearing would ensure they were lubed.
On the other hand it would take a hell of a tank slapper to ever seize the bearings, although I suppose on hotter climes the grease might melt out.

all the best - Bill
Title: Re: Steering Head Bearings!
Post by: LJ. on 08.07. 2007 22:41

I found it took a heck of a lot of grease as well! Cor Blimey! didn't my hand half ache afterwards, pumping all that stuff in!
Title: Re: Steering Head Bearings!
Post by: fido on 11.07. 2007 07:42
I don't think they were filled with grease from new. Certainly the A7SS  and B31 that I restored only had grease in the immediate vicinity of the bearings. This had been there a long time as in both cases it had gone hard, like varnish. I suppose the reasoning was that it was cheaper to waste a bit of grease when they needed new lubricant rather than waste expensive mechanic man hours in stripping down the steering head.
Title: Re: Steering Head Bearings!
Post by: G/F DAVE on 11.07. 2007 08:31
RE; steering head bearings, these were smeared with grease then fitted to the machine,  I can,t see the need to pump the head stock full of grease to obtain lubrication, Once smeared with grease it should stay on the bearings  for a long time ( no centrifugal force or heat issues). I use taper bearings as I have decent front brake fitted (duetto tls on tribsa) and find the taper kit easier to adjust , all the best Dave
Title: Re: Steering Head Bearings!
Post by: G/F DAVE on 28.07. 2007 19:22
RE; STEERING HEAD BEARINGS, I decided to make space in my workshop by hanging my spare a10 frames in the rafters and took a look at the head stocks,The plunger A10 1953 has a grease nipple at the bottom only ,which is directed into the outer race, this is a cast head stock with the tubes pinned and brazed into place .The tubes are open ended hence if you pumped grease into nipple with the idea of overflowing the bearing till grease spewed out you would have to fill the frame tubes first !! at least your frame wouldn,t rust from the inside out, Also noticed M20 has a cast headstock same system but main tube has a blank plate at top.Still would take a lot of grease though, all the best Dave...........