Author Topic: Yoke gap  (Read 1402 times)

Offline duncan32bsa

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Yoke gap
« on: 14.01. 2011 20:33 »
Hi All,
I feel like I'm assembling this bike by numbers...
As a change from the gearbox rebuild and the stalled swinging arm re-attachment, I thought I'd refit the front forks.
The thinking is, once I've got the front wheel on I can use that to align the rear to when I ream out the swinging arm pivot hole.
As always, it hasn't gone according to plan.
If line up the holes on the fork 'trousers' with the ones in the bottom yoke I can see there's a gap between the top of the trousers and the top yoke.
My first thought was that the top yoke cover would bridge the gap but it doesn't.
I'm a bit puzzled because I cannot easily see where I'm going to bridge the gap. The yoke fitting and steering column seem to have a fixed geometry once tight. Or do they?
I'm a bit reluctant to just over-tighten everything as the steering stem adjusting sleeve seems to bear on the bearing dust cap - maybe that's the problem?
Advice much appreciated as usual.
Thanks
Gary
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Online chaterlea25

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Re: Yoke gap
« Reply #1 on: 14.01. 2011 21:06 »
Hi Gary,
Is there a gap between the top yoke and the dust cover?
There shouldnt be!! the yoke should sit down on the cover, its pushed down by the top nut
If you have fitted new steering head bearings Are the cups fully home?
If taper rollers the yokes will be further apart than with the original setup, But not as much of a gap as you have?????

HTH
John O R
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Offline duncan32bsa

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Re: Yoke gap
« Reply #2 on: 14.01. 2011 21:53 »
Hi John,
the dust cover is touching. The bearings are the original balls but you may be onto something with the comment on the cups. I've looked at pre-stripdown pictures of the bike and they also show a gap. I'll check.
Thanks
Gary
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Offline duncan32bsa

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Re: Yoke gap
« Reply #3 on: 15.01. 2011 10:30 »
I'm replying to my own posts now. Possibly one of the first signs of madness....
In keeping with the story of this bike it looks like I may have the answer.
The bottom yoke has a cast-in number: 42-5013.
According to the parts book I need 42-5086 as my machine has the headlight cowl.
At this rate, I'll probably be able to build another A10 from the leftover/replaced parts.
Does anyone know what the difference is? (Other than a possible 1/4 length difference).
Interestingly, the cowl-less version should be 42-5015, different again.
Gary
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Online trevinoz

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Re: Yoke gap
« Reply #4 on: 15.01. 2011 23:48 »
Gary,
        I am surprised that you found a cast number on the bottom yoke. I can't find one on any of mine.
The one you have is most likely a 42-5012 as the part number is usually one less than the casting number.
This one will be OK as it was used on the early A10s and late Rockets.
The difference is usually only drillings.
The nacelle yoke has two tapped holes for the horn bracket and the Rocket type doesn't.
Your top yoke will have cast numbers also. I think 42-5036.
Again the Rocket has a different number as it is drilled and tapped for the instrument bracket but can be used with a nacelle.
Trev.
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Offline duncan32bsa

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Re: Yoke gap
« Reply #5 on: 21.01. 2011 12:52 »
And here (unbelievably) is the explanation for the gap. Can you spot the difference? Another paint job.
The strange thing is that it does not look like the small 'trousers' have been cut down.
Were there different kinds for different models?
Gary
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Offline wilko

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Re: Yoke gap
« Reply #6 on: 21.01. 2011 21:13 »
Is it C11 or C12?
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Offline beezalex

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Re: Yoke gap
« Reply #7 on: 21.01. 2011 21:27 »
Looks like you have a shroud off an A65 star.  A65's with this shroud used the "dropped" top yoke, hence the shroud is shorter.
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Alex

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