Forks (2007)

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Feb 22, 2007
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Removed the forks today and am in the process of installing a fork upgrade kit. My fork gaitors were quite dirty inside, probably from a slow leak somewhere. A few questions:

I noticed the fork stanchions have some pitting and corrosion on them. When I slid on the new fork oil seal, for example, I could hear it scraping against the corroded areas of the stanchion. Can I just sand these areas down (there isn't a lot of it), and assume the fork oil will keep them from corroding more? Or do I need to replace them completely?

My upgrade kit came with some paper washers. And while I haven't completely dismantled - yet - the lower fork damper tube components, I have not encountered any paper washer in the upper areas. In looking at the diagram, it appears there's supposed to be a paper washer on top of the fork top bush NMT. Is that correct? Again, my old set-up did not have a paper washer in that location.

The fork collars. Mine where abused repeatedly by the previous owners; obviously they used either big pliers or a pipe wrench to take them on and off. I'm not necessarily concerned about their appearance (rough) since they get covered up with the gaitors. But should they be pristine in order to prevent any future leakage? I know that probably has everything to do with the condition of the threads, which seem to be in okay condition.

I've got some Progressive springs ordered and will be installing them in place of the old ones. I was wondering, finally, what is recommended as the optimal fork oil?

Many thanks, in advance, for any help.

Cheers--

wrench
 

L.A.B.

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wrench said:
I noticed the fork stanchions have some pitting and corrosion on them. When I slid on the new fork oil seal, for example, I could hear it scraping against the corroded areas of the stanchion. Can I just sand these areas down (there isn't a lot of it), and assume the fork oil will keep them from corroding more?

That would probably work...for a while.



wrench said:
My upgrade kit came with some paper washers. And while I haven't completely dismantled - yet - the lower fork damper tube components, I have not encountered any paper washer in the upper areas. In looking at the diagram, it appears there's supposed to be a paper washer on top of the fork top bush NMT. Is that correct? Again, my old set-up did not have a paper washer in that location.

Yes there should be a paper washer between the top bush and the seal.


wrench said:
The fork collars. Mine where abused repeatedly by the previous owners; obviously they used either big pliers or a pipe wrench to take them on and off. I'm not necessarily concerned about their appearance (rough) since they get covered up with the gaitors. But should they be pristine in order to prevent any future leakage? I know that probably has everything to do with the condition of the threads, which seem to be in okay condition.

The collars retain the seals so provided they screw down correctly it should not matter what they look like.


wrench said:
I've got some Progressive springs ordered and will be installing them in place of the old ones. I was wondering, finally, what is recommended as the optimal fork oil?

SAE 20 oil was the original recommendation and that is what I use with progressive springs and it feels about right to me.
 
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It used to be a bit of a standard bodge to degrease stanchions, carefully apply araldite or other epoxy adhesive to the damaged areas, clean up with Scotch-Brite and fit gaiters at MOT (Ministry test time). I even think that it used to feature regularly in the tips in "Motorcycle, Scooter and Three-wheeler mechanics" :)

I have yet to meet anyone who has been able to satisfactorily describe the function of the paper washer. It sits there and eventually decomposes. Don't get me wrong, I always fit one because the Parts Book says so but I don't think it will cause problems if you don't.

Around SAE 20 is about right for the forks. 5 or 10 will let it top out with a clang. 30 will give you too much compression damping but it's not too critical if everything else is in order.
 
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wrench said:
Removed the forks today and am in the process of installing a fork upgrade kit. My fork gaitors were quite dirty inside, probably from a slow leak somewhere. A few questions:

I noticed the fork stanchions have some pitting and corrosion on them. When I slid on the new fork oil seal, for example, I could hear it scraping against the corroded areas of the stanchion. Can I just sand these areas down (there isn't a lot of it), and assume the fork oil will keep them from corroding more? Or do I need to replace them completely?

My upgrade kit came with some paper washers. And while I haven't completely dismantled - yet - the lower fork damper tube components, I have not encountered any paper washer in the upper areas. In looking at the diagram, it appears there's supposed to be a paper washer on top of the fork top bush NMT. Is that correct? Again, my old set-up did not have a paper washer in that location.

The fork collars. Mine where abused repeatedly by the previous owners; obviously they used either big pliers or a pipe wrench to take them on and off. I'm not necessarily concerned about their appearance (rough) since they get covered up with the gaitors. But should they be pristine in order to prevent any future leakage? I know that probably has everything to do with the condition of the threads, which seem to be in okay condition.

I've got some Progressive springs ordered and will be installing them in place of the old ones. I was wondering, finally, what is recommended as the optimal fork oil?

Many thanks, in advance, for any help.

Cheers--

wrench

Wrench, you're my guinnea pig now as I have been putting off my fork rebuild. :p

I hope my stanchions are rust free below the seal which they hopefully should be. I had no gaiters on my forks and the upper part of the stanchion looks great.

Good luck with the rebuild and let us know how things work out. I'll probably get to a dismantle of mine next week and while the lower legs are out for a polish I'm thinking of getting the yokes chromed.
 
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Feb 22, 2007
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Thanks L.A.B. and 79x100. Mucho appreciated. I'm heading back to the shop now to continue with the forks. I'm hoping I can just use the stanchions as they are. I'm spending SO much money on the bike I don't need any more surprises.

Another question: Regarding the triple trees, my upper and lower yokes were previously chromed for some reason (I think I read somewhere that they did not arrive from the factory chromed). The chrome has chipped off significantly on the right front of each one --perhaps suggesting some kind of collision at one time. Any ideas on how to treat them to clean them up? I could probably try sanding them down and then painting them, but the chips seem a little too deep not to be noticeable. If I was going to fill them with something, what might it be? I think structurally they are fine, and I can live with them as is for a while if I must.

Thanks again.

wrench
 
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You probably just need them rechromed.

They did not come from the factory like that so someone had it done.

Question. When I send my yokes off for a chrome, I obviously don't get the steer tube done, but what about where the stanchions fit through the yokes?

Would I get that inside part of the yokes chromed or leave it alone?
 

L.A.B.

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My own yokes had been chromed and were rust pitted, I just rubbed them down and silver painted over the remains of the chrome, and the finish has lasted fairly well.
 

Ron L

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Wrench,
I'm afraid that sanding on the rust pits will (maybe) work for a short while before destroying your new seals. You can often get new extended tubes for quite cheap (the last I got were $20 a pair). If you have a friend with a lathe, he can cut these down to size easily. For $20 and couple of beers you don't need to worry about ruining new seals. Even a used set can work as when you cut down the tube you are creating a new sliding surface.

I have found that the paper washer does seem to cut down on fork seal failure. Not sure why, but there seems to be less seepage when the washer is used.

As for the fork yokes, a chrome shop can de-chrome them and then you can prime and paint.

Never use a pipe wrench on fork seal collars. I wrap the collar with emery cloth then clamp the leg in a vise. Turn the leg with the front axle and the fork seal collar will unscrew easily and undamaged.
 
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Coco said:
Wrench, you're my guinnea pig now as I have been putting off my fork rebuild. :p

Most definitely, and gladly so. I owe you. They've (the forks) actually been a joy to work on once I figured out how they 1) worked in the first place, and 2) how the various parts fit together.

I hope my stanchions are rust free below the seal which they hopefully should be. I had no gaiters on my forks and the upper part of the stanchion looks great.

You're most likely in good shape, then. I probably should have guessed mine would be pitted and rusted with the gaitors covering everything. Murphy's Law, right? I'm going with the short rubber "boots" instead of gaiters (UK refers to our "boot" as a gaiter, me thinks).

Good luck with the rebuild and let us know how things work out. I'll probably get to a dismantle of mine next week and while the lower legs are out for a polish I'm thinking of getting the yokes chromed.

I bought a combo buffing/grinder machine a few months back and have been getting around to polishing some bits. I'm just back from polishing one of the sliders(messy, filthy work. Always come home looking like a coal miner, but with less cash in his pocket). This bike really cleans up well. You'll appreciate the difference when you get your sliders back.

Thanks Coco.

wrench
 
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Ron L said:
I'm afraid that sanding on the rust pits will (maybe) work for a short while before destroying your new seals.

Ron, this was actually my concern, as every time I run my new seals over them I cringe. In fact, even after attempts at sanding the malignant areas down, I cannot figure out why the seals just don't sail over them without crying in protest. You can feel and hear their literal displeasure....

You can often get new extended tubes for quite cheap (the last I got were $20 a pair). If you have a friend with a lathe, he can cut these down to size easily. For $20 and couple of beers you don't need to worry about ruining new seals. Even a used set can work as when you cut down the tube you are creating a new sliding surface.

I a complete dumb-ass and newbie in bike restoration, so please forgive. I just don't know what extended tubes are or where to get them. I have, unfortunately, no mechanic pals, nobody I know of with a lathe. I do pride myself on learning fairly quickly, though, so I'll figure it out. I really want to do the majority of the work on this bike myself, for financial reasons but primarily out of a desire to learn and make the bike my own. I just don't want you (or anyone here) to take my ignorance for a lack of gratitude. I am continually amazed at the time folks take here to educate.

As for the fork yokes, a chrome shop can de-chrome them and then you can prime and paint.

Might that cost about as much as a new set of yokes? Can't I solder some kind of alloy in the crevices, sand it all down, and powder coat (learn yet another new skill) the unit?

Never use a pipe wrench on fork seal collars. I wrap the collar with emery cloth then clamp the leg in a vise. Turn the leg with the front axle and the fork seal collar will unscrew easily and undamaged.

I tried using a strap wrench on the seal collars. Didn't budge. I then used a pipe wrench, and the collar gave way. I wrapped it in paper towels before doing so, and didn't damage it. But heck, the thing has been attacked by various previous owners myriad times. Yes, I've got a pair of very sorry lookin' seal collars. But the threads are good. Looks like they would still work.

I agree with you, though. The pipe wrench will play havoc on the collars. But I am curious as to why, apart from appearances (the part is covered by the boot/gaiter, after all), treating the collars so carefully is specified. Won't it do its job just fine if the threads aren't damaged? And why did the engineers at Norton design such a part? Why not make it a part that some kind of wrench can grab on to?

And in conclusion, and in thanks, I now know how to put the collars back on. Mucho appreciated!

As always, thanks, thanks, thanks.....

wrench
 
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Ron L said:
As for the fork yokes, a chrome shop can de-chrome them and then you can prime and paint.

Never use a pipe wrench on fork seal collars. I wrap the collar with emery cloth then clamp the leg in a vise. Turn the leg with the front axle and the fork seal collar will unscrew easily and undamaged.

Good info. I'll try a strap wrench but if that doesn't work, the emery cloth and vise will do nicely.

Wrench as far as I know your original stanchions can be hard chromed again, but it's probably cheaper just to buy a new set.

If it were me, I would just buy a new pair and be done with it. Your bike seems like mine and is running (mine's NOT running right now) on cash stuffed into the tank rather than gas. At this point I don't worry about an extra hundered dollars here and there since I've gotten in so deep already.

I hope everything works out, and I'm sure it will.
 
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wrench said:
Coco said:
I bought a combo buffing/grinder machine a few months back and have been getting around to polishing some bits. I'm just back from polishing one of the sliders(messy, filthy work. Always come home looking like a coal miner, but with less cash in his pocket). This bike really cleans up well. You'll appreciate the difference when you get your sliders back.

Thanks Coco.

wrench

You're more ambitious than me. I work on my bike at work so I don't want to fill the place with polishing goo. When it cones to that sort of thing I would rather pay for the servive than have the satisfaction of doing it myself. Polishing really is filthy work.
 
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Any workshop which deals with industrial or commercial vehicle hydraulic cylinders will have access to the sort of hard chroming and grinding equipment that you need and can also correct slight deviations. I suspect that the quality of tubing as original was better than the currently available parts so re-chroming is an option.

If the decorative chrome on your yokes (triple trees) is starting to lift then attacking them with a rotary wire brush will probably get the rest off.

In the UK, gaiters usually refers to the full coverage rubber bellows. The short covers are really just dust covers.

It's strange that the seal retainers have no means for loosening. They were obviously descended from the full length chrome shrouds on Dominators and they did have holes for a peg spanner ! The longer term answer is to replace the rings with stainless copies and assemble with lots of copper grease. They can usually then be disassembled by turning the dust caps by hand.
 
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Coco said:
If it were me, I would just buy a new pair and be done with it. Your bike seems like mine and is running (mine's NOT running right now) on cash stuffed into the tank rather than gas. At this point I don't worry about an extra hundered dollars here and there since I've gotten in so deep already.

Pretty much the conclusion I've come to, Coco. Just not worth hassling over a few bucks, I guess. And I don't want to have to rebuild these things next season already.

w/
 
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79x100 said:
I suspect that the quality of tubing as original was better than the currently available parts so re-chroming is an option.

Hard to say with this bike(!).... the way the previous owner hodged-podged the the entire machie.

If the decorative chrome on your yokes (triple trees) is starting to lift then attacking them with a rotary wire brush will probably get the rest off.

That makes sense. Will give it a go.

The longer term answer is to replace the rings with stainless copies and assemble with lots of copper grease. They can usually then be disassembled by turning the dust caps by hand.

I see Old Britts carries the better versions. Again, to use Coco's phrase, more money in the gas tank.

Thanks!

w/
 
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Pipe wrench

Just thought I would give a word when it comes to using a pipe wrench on anything. Not a good idea most always causes damage, if you must, use a piece of emery cloth grit side on part you are trying to remove this will help prevent damage . A strap wrench does not always work however there is a device called a chain wrench like a pair of vise grips with a length of chain attached this tool has a better grip and will not cause damage to your part. Just thought I'd put in my 2 cents worth DOXFORD
 
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Just to reinforce what others have said about using a vise (larger is better) to grip the collar and the axle to turn the leg as being a good method for doing this job, using a propane torch to moderately warm the top of the fork leg where it meets with the collar makes a huge difference to the ease with which even a fork that has not been touched for years can be dissmantled.
 
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Thanks to all in helping out with the forks. Both are fully dismantled now. Oddly, the right fork had a muddy, reddish-colored oil in it, and today, when I took apart the left fork, it was filled with a distinctly pea green-colored oil. Very strange. I decided to just get new stanchions (ordered today), and also ordered a pair of fork damper rods, as these were terribly corroded as well. As previously indicated, the fork collars are rough but I think the damage to them is primarily on the exterior.

Thanks again,

wrench
 
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Coco said:
Cool.

Report back once everything is finished.

It's a deal. And I hope the progress on your bike is going well.

Was just noticing in the Tech Digest (just finally found it.... I'd misplaced the thing), a section entitled Front Fork Lubricants. It recommends 150cc per fork of a 30W; it lists the factory recommendations, but then goes on to say that they won't work nearly as well as modern fork oils such as Bel Ray or Kal-Gard 30W. It goes on to say that "20W can cause topping or bottoming in warm climates."

There may be some disagreement on this, I take it(?).

w/
 
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