AJS & Matchless Owners Club

Steering head assembly.
I am doubting whether all is well with my G3s' steering head bearing assembly. My current G3 is about number five in the ownership list, but this one does not “feel” completely right.

Riding in a straight line it almost feels like there is some position ½ a degree or less to either side of dead ahead that the bike wants to run in. The bearing cups and ball bearings were all replaced with brand new during rebuild. I have followed adjustment procedures to the letter, but it still does not “feel” completely right.

With the yoke pinch bolts slack I adjust the crown stem nut system until there is no end play perceptible. Or as the manual says “ Adjustment should be such that no end play be felt, yet the bearing are free to rotate and are not over tight”.

I have covered about 800 miles or so since rebuild, and I am seriously thinking of stripping down the steering head to see if I can spot anything wrong.
All help and suggestions appreciated. Is there anything I should be looking for

Leo

If the bearings are good, then I'd check the tracking (are the wheels pointing dead ahead?) and offset (are the wheel centres exactly in line?). Anything amiss here can give the feeling you describe...

PS: when adjusting head bearings, you want the steering head to rotate completely freely, but with no discernible play when pulling/pushing the front wheel. Any 'drag' from the bearings means you've set them too tight; any play means they are loose. If it changes from one to the other depending on the steering position, then the bearings are shot.

Just a thought... have you tried slackening off the steering damper a wee bit?

Nice thought, but I have no steering damper fitted.
Leo

In some ways the feeling is a little bit like when you run along a white line, similar but not quite as pronounced.

Leo

Three thoughts

• Front and rear out of line but this would tend to feel wrong on one side rather than both as described.
  Are you using different front tyre from the sort you are used to, maybe the front tread pattern does not suit the bike.
  Did you overtighten the steering bearings when first setting it up, an overtightened head race will give exactly the syptoms you describe especially when slackened off again, the track just gets slightly marked and feels wrong ( yes yes been there done that).
  Does the rear wheel run true, a slight wobble in it can produce weird steering.

Ah well that's 4 thoughts

It is not unknown for the bearing cup to move in the frame. My answer has been on many rebuilds to Araldite the cup into the frame, assemble the
the yolks and adjust before the Araldite goes off ,then leave overnight then carry on with the assembly.This ensures that the cups are centred and
rules out the constant head bearing adjustment. Should you have to remove the cups in future a tap with a hammer will remove them
Tony

Hi Tony,

Yes I do have evidence that the races have been on the move in the frame cups, the underside of the races are highly polished and the races are sloppy in the frame cups.

This solution had drifted across my list of a possible cure, and seems feasibly. Would you consider this to be a long term solution? Any particular epoxy in mind.

Leo

I am warming to Tony's suggestion of epoxy, but when I have just done an initial look on the internet for a metal-to-metal epoxy they all seem rapid hardening, six minutes or so.
I think I would need rather more than six minutes to apply and assemble the head stock in the correct position.
Leo

Leo, hobby shops should be able to supply slow cure epoxy, and it could be 1 hour, 4 hour. 24 hour etc.
Rob C