Steering head adjustment on G2

Information relating to the Matchless G2 or AJS Model 14 250cc Lightweight
Richard Hyatt
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Steering head adjustment on G2

Post by Richard Hyatt »

Hi all
Lightweight forks on our G2.
Can anyone please explain the science behind the head race adjustment .
All my other bikes , I slackened the lower fork yoke pinch bolts and the adjustment /squeezing of the races is done by pushing the top fork down , thereby pushing the stanchions downwards through the lower yoke. This keeps the yokes parralel.
On the G2 , there are no lower fork pinch bolts , and the lock nut and adjuster nut just seem to push the lower fork and legs upwards into the top yoke.
Mechanically, I can't see how the 2 yokes are kept parallel ?
Am I missing something?
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Rob Harknett
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Re: Steering head adjustment on G2

Post by Rob Harknett »

Don't know why you loosened pinch bolts. Steering adjustment should be no different if it has Tele or Girder forks.
Take weight off the fork so they have no contact with the ground. Some may forget, if fitted, slacken off the steering damper knob. Loosen the top nut, adjust the bottom adjusting nut. Do not adjust too tight so that bearings will bind. Tighten the top nut. If there is play you should feel it by grabbing the fork legs still free with the wheel off the ground.. Keep bearings well lubricated.
SPRIDDLER
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Re: Steering head adjustment on G2

Post by SPRIDDLER »

Richard didn't say he loosened the pinch bolts Rob; those L/W forks on the standard G2 don't have pinch bolts - see pages 30 and 31 of the owners manual.
http://archives.jampot.dk/book/Owners_m ... Manual.pdf
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Richard Hyatt
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Joined: Sun Jan 27, 2019 8:52 pm
Location: Dorset

Re: Steering head adjustment on G2

Post by Richard Hyatt »

Thank you both for replies.

I've studied the books and drawings for ages , but couldn't work out mechanically how the yokes were kept parallel and thereby the races parallel .
I've taken up the play , but still mystified as to the mechanics of the adjustment.
Cheers though.
Paul R
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Re: Steering head adjustment on G2

Post by Paul R »

I don't think the top and bottom yokes do remain absolutely parallel otherwise there would be no other way of taking any slack out . The top bolt is tightened up then the large nut under the bottom yoke tightened to remove any residual play then locked into position by the second nut. Mine did have some thin shims under the top yoke ,not shown in the drawing to lessen the amount of flex needed to remove any play . If these were a standard feature or not i have no idea .
Richard Hyatt
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Re: Steering head adjustment on G2

Post by Richard Hyatt »

ah ok
thank you

maybe I have been doing it wrongly

I have not touched the top nut at all.

just backed off the lower lock nut - nipped up the play by the lower adjuster nut - and then locked up lower nut again.

i'll try it your way - I read it in the book the way above !!
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Rob Harknett
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Re: Steering head adjustment on G2

Post by Rob Harknett »

SPRIDDLER wrote:Richard didn't say he loosened the pinch bolts Rob; those L/W forks on the standard G2 don't have pinch bolts - see pages 30 and 31 of the owners manual.
http://archives.jampot.dk/book/Owners_m ... Manual.pdf
No not on the light weight Nevvile, but did on ohe bikes.
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Rob Harknett
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Re: Steering head adjustment on G2

Post by Rob Harknett »

Richard Hyatt wrote:ah ok
thank you

maybe I have been doing it wrongly

I have not touched the top nut at all.

just backed off the lower lock nut - nipped up the play by the lower adjuster nut - and then locked up lower nut again.

i'll try it your way - I read it in the book the way above !!
Its not my way, its the books way. Adjusting lightweight forks is the same as I said in the book, front wheel off ground etc. but no mention of slackening a steering damper as it may not have one
Ashampoo_Snap_08 July 2019_17h45m06s_001_.jpg
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Richard Hyatt
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Location: Dorset

Re: Steering head adjustment on G2

Post by Richard Hyatt »

Thank you all.
I get the idea , but these diagram numbers don't relate to the actual lightweight forks .
Not to worry , I'll get there
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Rob Harknett
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Re: Steering head adjustment on G2

Post by Rob Harknett »

They relate to G2 forks. So what forks year model have you got fitted. Even if the numbers and parts differ in appearance, method of adjusting bearings is the same for all years models. pre war girder forks onwards. With the wheel off the ground, you slacken off the top fitting adjust by the fitting below it, then lock up the top. Same principle as you adjusted wheels pedals cranks etc on your push bike when you were a child.
Locked