Fork yokes - on-the-wonk!

Helpful information and requests for assitance and advice
DavidHulse
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Joined: Mon Dec 17, 2018 1:49 pm
Location: Essex UK

Re: Fork yokes - on-the-wonk!

Post by DavidHulse »

Thanks Clive and Mick. Those replies are brilliant! I didn't know how to get the column out of the yoke but it makes sense now. (I knew from the parts list that there was a circlip in there but I couldn't see it.) However, I'll try Mick's suggestion to try to correct the distortion before I try to take the yoke apart. Just to confirm, I measured it all again today and the column is about 2mm away from vertical (leaning to the right) and the yoke and crown are 2mm away from parallel (wider on the left). So tomorrow, I'll have another go at sorting it out, armed with the new information. Watch this space....
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clive
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Re: Fork yokes - on-the-wonk!

Post by clive »

Definitely listen to an engineer before a bodger. :rofl:
clive
if it ain't broke don't fix
DavidHulse
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Joined: Mon Dec 17, 2018 1:49 pm
Location: Essex UK

Re: Fork yokes - on-the-wonk!

Post by DavidHulse »

New update. I've tried to straighten the misalignment using studding and washers but, although I can pull it straight when under tension, it goes back to where it was as soon as I release it. I think it will need the help of a blacksmith to put it right, and that's not very practical at the moment. I've considered taking the crown apart but, having checked out the (non) availability of replacement parts, I've decided against that, too, for the time being. It would be very interesting to see if it can be straightened by removing and reinstalling the column in a different position, so I'll keep that on ice for future reference. In the meantime, I've put it back together, using an old fork shroud leather washer as packing under the bottom collar, which seems to have done the trick. The difference between the two legs is hardly noticeable so, if it doesn't affect the steering, I'll leave it like that. If there is a problem, I'll take it apart again and try to reposition the column to eliminate the difference between the left and right forks. That should be a lot easier now I've got the home made fork puller. Fingers crossed! Thanks again for all your help Clive and Mick. All the best. Dave.
Mick D
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Re: Fork yokes - on-the-wonk!

Post by Mick D »

Hi

Two fairly easy options to try:

Have you been over correcting the distortion? You need to do this to negate the springiness in the material and assembly - try going progressively past the correct alignment and see if it improves. It's also better if you use two studs at the same time - one to spread and one to compress.

If the above fails you can use the fact that the lower yoke and stanchions 'set; the alignment.

With the yokes assembled in the headstock compress the wide side until correct alignment is achieved, fit the fork assembly, (covers rings etc.), to the free side and fully secure it, pinch bolt and top nut.

Remove the studding and fit the other assembly leaving the stanchion short of the top yoke by the amount of remaining distortion, tighten the pinch bolt and use the top nut to draw the yokes into alignment.

For a mis-alignment of 2mm there should be no need to involve heat or dis-assembly.

Regards Mick
DavidHulse
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Joined: Mon Dec 17, 2018 1:49 pm
Location: Essex UK

Re: Fork yokes - on-the-wonk!

Post by DavidHulse »

Thanks for the additional advice, Mick. I did try going beyond the straight position to allow for it to relax back but it didn't work. Maybe I could have gone further but I was anxious not to break anything. I think your other suggestion to use the other leg to align it should work though; and certainly I'll try that if I have to readdress the problem when I get get it running, hopefully in a few weeks' time. Cheers. Dave.
DavidHulse
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Joined: Mon Dec 17, 2018 1:49 pm
Location: Essex UK

Re: Fork yokes - on-the-wonk!

Post by DavidHulse »

On second thoughts, I'll try it today, before I put the wheel and mudguard in. Might save doing it twice! I'll let you know how it goes. Thanks.
DavidHulse
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Posts: 56
Joined: Mon Dec 17, 2018 1:49 pm
Location: Essex UK

Re: Fork yokes - on-the-wonk!

Post by DavidHulse »

Unfortunately nothing worked. I tried both of the options above but it always sprung back to where it was before. Trying to tighten down the top yoke to take up the slack only caused the head bearings to bind badly, even with new balls and satisfactory races. So I've gone back to the plan of assembling it with packers on the stanchions; but I've left them out for the time being in the, probably forlorn, hope that when I get the front wheel in and bounce the suspension a few times, it may settle a bit and reduce the amount needed. If I ever get it sorted properly, I'll revisit this thread and let you know the outcome. Thanks guys.
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