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Re: Forks. How to undo those top nuts???

Posted: Sat Nov 20, 2010 11:35 am
by Chuey
ME 109 wrote: Poor engineering seems to often result in very little 'lip' available to get a proper tool in there to drive/pull the outer races.
Now if there is something to complain about with regard to the head bearings, that's my candidate!

Chuey

Re: Forks. How to undo those top nuts???

Posted: Sat Nov 20, 2010 11:59 am
by dougie
Chuey wrote:
ME 109 wrote: Poor engineering seems to often result in very little 'lip' available to get a proper tool in there to drive/pull the outer races.
Now if there is something to complain about with regard to the head bearings, that's my candidate!

Chuey
I agree.
I had to carefully cut almost through mine, then crack them with a punch!
PITA!!!

Re: Forks. How to undo those top nuts???

Posted: Sat Nov 20, 2010 2:25 pm
by dwire
Duane Ausherman wrote:
ME 109 wrote:Tightening the 3 top nits seems to be the main cause of a good alignment process going bad, even with a torque relief bar. ime.
Yes, nits. I did a lot of head scratching to work out how to counter this problem, but counter it I did.
Please explain how you did this. The torque relief bar is the best that we could come up with all those years ago, but I would love to learn a better way.
I am guessing that is what he used, but indeed there are a handful of things/ways contrived to do the same thing on the same spot. I used several devices in doing my last, I also jotted down somewhere (lost in the move right now...) a drawing and dimensions for something that I thought would work better than the scarp angle-iron sort of methods that accomplished the task at hand the last time. If anyone is all that concerned, once they are found, I'll publish them with a bunch of other "nifty" prints... (Both my designs and those old German Matra's... )

BTW Duane, would you at least like HD scans of those ancient BMW internal/Matra prints for the site??? Let me know, you know how to reach me... :-)

Re: Forks. How to undo those top nuts???

Posted: Sat Nov 20, 2010 3:01 pm
by Airbear
dougie wrote:
Chuey wrote:
ME 109 wrote: Poor engineering seems to often result in very little 'lip' available to get a proper tool in there to drive/pull the outer races.
Now if there is something to complain about with regard to the head bearings, that's my candidate!

Chuey
I agree.
I had to carefully cut almost through mine, then crack them with a punch!
PITA!!!
With mine there was insufficient 'lip' to use a screwdriver but this worked a treat ...

Image

It's a length of 8mm stainless rod, bent and then cut. It's a punch that can see around corners.

Re: Forks. How to undo those top nuts???

Posted: Sat Nov 20, 2010 3:04 pm
by dougie
Airbear wrote:It's a length of 8mm stainless rod, bent and then cut. It's a punch that can see around corners.
That's excellent - will keep it in mind for next time.

Re: Forks. How to undo those top nuts???

Posted: Sat Nov 20, 2010 3:47 pm
by ME 109
Duane Ausherman wrote: Please explain how you did this. The torque relief bar is the best that we could come up with all those years ago, but I would love to learn a better way.
Firstly, I did use a torque relief bar. But what I found was that when the forks were spot on according to my piece of glass, torquing the nuts moved the forks out of alignment.
The top nuts were acting on the top plate and twisting it, even after making sure the top plate was flat and free of any small burrs that may have been catching. I even greased the contact surfaces of the top plate and nuts but things still moved.

I last aligned my forks when I hit a kangaroo nearly 18 months ago, so precise details are foggy but basically what was needed was to start torquing the top nuts with the forks 'out of alignment' so that torquing bought them back into alignment.

My fork legs were bent beyond a point where I was comfortable having them straightened so two new/second hand legs were found. Checking the new legs for straightness showed them to be spot on, as I couldn't fit a .05mm feeler gauge anywhere when rolling them together.
The triple tree was twisted as well so I used my bent legs and a 6' length of timber to bend it back, swapping the known good legs with the bent legs and tweaking until the glass showed zero rocking. At that point the alignment process could continue.
It took me about two hours to get the oe fork brace correctly 'shaped' so that it made no difference to the freely spinning axle when the four bolts were torqued.
My RS displays perfect manners at lower speeds with no hands on the bars.

Re: Forks. How to undo those top nuts???

Posted: Sat Nov 20, 2010 4:43 pm
by dougie
ME 109 wrote:I used my bent legs and a 6' length of timber to bend it back.
You gotta love a bike that can be fixed with a 6' length of timber!

Re: Forks. How to undo those top nuts???

Posted: Sat Nov 20, 2010 5:45 pm
by ME 109
dougie wrote:
ME 109 wrote:I used my bent legs and a 6' length of timber to bend it back.
You gotta love a bike that can be fixed with a 6' length of timber!
Those '81 triple trees are mighty strong!
I'll add that after hitting the roo and bending the forks considerably, we rode home through the mountains not sparing the horses. Apart from the handle bars being off centre, I couldn't tell there was a problem. Impressive to say the least.
Very low speed tight left corners did however feel somewhat strange.
The mountain sections were after we had called into Mals' at Dubbo and borrowed his 3' jimmy bar to manipulate the fork brace!
Prior to the 'manipulation' there was no movement in the forks, they were stuck. I called it stuction.
The stuck front end actually felt rather good at times, making me want to preload the fork springs when I repaired the bike.

Re: Forks. How to undo those top nuts???

Posted: Sat Nov 20, 2010 10:23 pm
by gertiektn
I think I would try to loosen the outer then the inner... in that order.
Use a box wrench and a hard rubber mallet. Whack! \\

Caution!
I have never seen one of those before.

My dad always said, if they put it on... it will come off. He was always right.

JIm, Ketchikan, AK

Re: Forks. How to undo those top nuts???

Posted: Sun Nov 21, 2010 11:38 pm
by Roy Gavin
After 350,000 km there is enough slop in my forks that they were still free after tightening the top nuts , without using a torque relief bar. I just followed the instructions in the workshop manual for my BSA.

It is petty close to Duane's method, except that they use a jig with four V s instead of the plate glass.