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How to remove Bearing cups from headstock
Posted: Sun Jun 26, 2011 4:18 pm
by Keith.owen
Hi,
Does anyone have a tip on how to remove the bearing cups from the headstock of a frame?
The handbook suggests that they can be drifted out but I don't see how. There is a gap underneeth the cup between it and the internal body of the headstock but I don't see how, given the distance from the opposite end and the shallow angle that is afforded that, it is possible to engage sufficiently to do this. Is there a special tool?
Also, I have attempted to drive out the dowel in the bottom yoke to remove the steering damper......but even on a bench it doesn't seem ready to just be driven out (again as the handbook suggests). Any thoughts?
Any suggestions will be much appreciated!
Thanks,
Keith

Posted: Sun Jun 26, 2011 5:11 pm
by tony.barnett
I've removed headstock cups by running a seam of weld round them - they just fall out. Obviously they're no good after that but why else would you remove them?
Re: How to remove Bearing cups from headstock
Posted: Sun Jun 26, 2011 9:41 pm
by john.nash
If you don't have a welder, then I usually use a small cutting wheel in a dremel tool.
just cut a section out (top to bottom) and you can usually drift it sideways and then down.
Re: How to remove Bearing cups from headstock
Posted: Sun Jun 26, 2011 11:17 pm
by Wali.Badger.Taylor
As tony says just run a mig bead in them and they drop out!
Posted: Mon Jun 27, 2011 10:37 am
by pete.collings
If you want to reuse the bearing cups, or get them reground for reuse if not too badly worn, I have used a piece of around 1/2" square bar of 12-18" length, with one end heated to red and then flattened and curved to match the inner edge of the cup (it does not have to be accurate, just to rest firmly on the protruding edge of the cup as seen looking down the headstock hole).
Then locate the curved end onto the lip from the opposite end of the headstock, and tap (firmly?) working your way around to gradually push the cup down and out.
I used this method when fitting modified BSA taper roller bearings to a swingarm frame, where the cups/cones were in good condition but had been covered in stoving, and were reusable on another frame after carefully removing the stoving coat.
Removing the steering damper cotter pin may require some force, especially if the end has been distorted when fitting. Look carefully at both ends to see if one is in better shape than the other, and drift out with a drift of lesser diameter, such that when using any necessary force you do not tend to distort the outer edge of the pin. Needless to say, care is need to avoid the drift slipping on the rounded shape/greasy surface of the pin and making a dent in the bottom yoke, or worse still your hand!!
Posted: Mon Jun 27, 2011 1:35 pm
by Vincent.vanGinneke
If you manage to get them out with a drift like Pete describes, here's what I did:
: Nail the cup onto a piece of flat wood, clamp this lot in a drillingvice.
Add all the balls (20) + grinding paste + some light oil.
Put cone in it and place this all under the pillar drill (if you have one..)
Put a thick piece of rubber (a ring preferably) between drill chuck and cone to even out any offset.
Lower chuck onto cup & cone, switch on and keep a light pressure on this lot by attaching 'a suitable weight' to the drill handle.
At first there is a rumbling of all the balls going over the dents, this sound evens out after a while.
Add extra oil and paste now and then.
When you hear a even 'grinding' noise they are ready.
For fitting; use new balls.
What I dont know is ; are these cups & cones hardened all the way through or only surface hardened ?
Until now (2800Km) my NG behaves o.k. with this 'balls treatment'
regards, Vincent
Re: How to remove Bearing cups from headstock
Posted: Wed Jun 29, 2011 12:14 pm
by Keith.owen
Hi everyone,
Thanks for the guidance.
Unfortunatley my facilities are a bit limited and so is teh Basingstoke area work machine shops etc. Sadly i don't have an anvil and don't think management would appreciate me attempting to attain red heat on the kitchen gas ring!!!
Cheers!!!
Keith

Posted: Wed Jul 13, 2011 10:14 am
by Keith.owen
Hi all,
Just a quick update on this.
Yesterday a friend who has a pull hammer assisted me in removing the cups (without damage - but this is bye the bye becuae I'll replace them anyway as a matter of course). We did have to heat the headstock fisrt, but since the frame will be re-painted this does not matter.
Keith
Posted: Wed Jul 13, 2011 2:43 pm
by robjameson
Just for reference then - me and Dad make this drift tool for doing the same job on my '57 swinging arm.
Made from 1/2'' round bar bent about 2/3rds down and filed flat on the bottom. Works a treat as long as you give it a good whack and use some colourful language.
Re: How to remove Bearing cups from headstock
Posted: Fri Oct 21, 2016 5:05 pm
by keithberry
hi Keith did you get the pin out of the bottom? if so how mine will not budge !!!!
cheers