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Front fork rebuild questions


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Evening all, I come in search of knowledge and advice. I'm rebuilding the forks on an 89 MkII and I've run into some oddities.

 

Quick background, someone previously has been into the bike who shouldn't have. When I went to take the handlebars off, both pinch bolts were backed way out. There are other things like this with the bike.

 

So, I create a tool to disassemble the forks (worked well, cheap, write up to follow if anyone is interested.) and got things separated. The bottoms of these forks have been beat to death! The hole in the bottom that the allen bolt should come out of was so mangled that judicious use of a dremel tool was necessary to get the bolt all the way out. Once everything was apart, it appears I have some issues.

 

1. I appear to be missing the tapered spindle, part #26H-23173-00-00 from one side. What the heck? I've looked everywhere, don't THINK I could have lost it, but maybe.

 

2. And this is where I could use some guidance. There are still some parts "stuck" in the bottom of the upper fork tube. I can see and feel what looks like a white plastic notched or "castellated" washer type part, and there appear to be some parts "above" that. I've tried some judicious tapping with an appropriately sized socket to drive them out, but don't want to use too much force on these parts.

 

3. Neither fork as, as far as I can find, the two washers #26H-2319L-00-00 or the single valve spring #26H-2319M-00-00. I'm wondering if the forks could have been assembled improperly, and now those parts are jammed in the bottom of the fork tube.

 

4. The fork springs that were in the bike are about 75% of the length of the Progressives I'm replacing them with. I'll post pics, but the difference is ridiculous. The forks had absolutely no pre-load on them whatsoever, even with some gargantuan spaces made out of electrical conduit.

 

So, should I continue to try to get the parts out of the bottom of the upper fork tube, or are they supposed to be where they are? I'm really thinking they need to come out, but would like other opinions.

 

Thanks everyone!

 

Paul

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Ever thought about just getting another pair of forks? These tubes might be bent, also. It sounds like you might be into more for parts and damage than you could pick up another set for.

 

Just my opinion, good luck,

 

Dan

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Evening all, I come in search of knowledge and advice. I'm rebuilding the forks on an 89 MkII and I've run into some oddities.

 

Quick background, someone previously has been into the bike who shouldn't have. When I went to take the handlebars off, both pinch bolts were backed way out. There are other things like this with the bike.

 

2. And this is where I could use some guidance. There are still some parts "stuck" in the bottom of the upper fork tube. I can see and feel what looks like a white plastic notched or "castellated" washer type part, and there appear to be some parts "above" that. I've tried some judicious tapping with an appropriately sized socket to drive them out, but don't want to use too much force on these parts.

 

3. Neither fork as, as far as I can find, the two washers #26H-2319L-00-00 or the single valve spring #26H-2319M-00-00. I'm wondering if the forks could have been assembled improperly, and now those parts are jammed in the bottom of the fork tube.

 

4. The fork springs that were in the bike are about 75% of the length of the Progressives I'm replacing them with. I'll post pics, but the difference is ridiculous. The forks had absolutely no pre-load on them whatsoever, even with some gargantuan spaces made out of electrical conduit.

 

So, should I continue to try to get the parts out of the bottom of the upper fork tube, or are they supposed to be where they are? I'm really thinking they need to come out, but would like other opinions.

 

Thanks everyone!

 

Paul

 

Yup, who ever did this, screwed up big time...............

 

The white plastic is supposed to fit into a groove in the damper rod, just below the top of it. The OEM springs are very short compared to the progressives (as you have seen).

 

:080402gudl_prv:

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Ever thought about just getting another pair of forks? These tubes might be bent, also. It sounds like you might be into more for parts and damage than you could pick up another set for.

 

Just my opinion, good luck,

 

Dan

 

 

:sign yeah that:

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Thanks everyone for the comments. I agree that there are some safety concerns here, and I want to make sure I do this right. I'm on the lookout for a set of replacements. Oddly enough, I have a replacement MkI set but not a MkII. Think I just missed a set of those from Hess4less.

 

Just to clarify things a bit, I got the digital camera back and here are some pics. Assuming they stay in order:

 

1. The handlebar pinch bolts, as I found them when I removed the cruise control unit. Not a confidence builder.

 

2. Comparison of the springs that were in the bike with the Progressives that are going in. You can see the big conduit spacer on the far left.

 

3. This is looking "up" into the upper fork tube, as it would be assembled. You can see the white plastic notched piece that seems to be stuck in there. I can feel what seems to be a metal washer "above" it, once again as it would be assembled.

 

4. Side view of the upper tube. I can see some sort of metal washer partially blocking the oil passage. Just don't think it's supposed to be there.

 

Hopefully that helps the collective wisdom. I'm going to mess with it some more today and I'll let you all know of any changes or additional info.

 

Thanks for the help!

 

Paul

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Thanks everyone for the comments. I agree that there are some safety concerns here, and I want to make sure I do this right. I'm on the lookout for a set of replacements. Oddly enough, I have a replacement MkI set but not a MkII. Think I just missed a set of those from Hess4less.

 

Paul

 

If the Mk1 upper tubes are good, why not use them, as I believe the difference is in the lower legs (caliper mounts & anti dive).

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IF, you decide to completly replace the Fork assembly. Be sure to replace the Steering head bearings as long as its all apart. If bike is over 50K, good time to do this.

 

As to the Progressive springs !! Deffinatly use those !!

 

You will find that with those springs installed, you can run 15Wgt fork Oil, and NO air pressure. Ride will be great.

 

Also, install the " SuperBrace "

 

After you complete all this work you will find your bike drives MUCH Better, then with the Stock front end.

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IF, you decide to completly replace the Fork assembly. Be sure to replace the Steering head bearings as long as its all apart. If bike is over 50K, good time to do this.

 

As to the Progressive springs !! Deffinatly use those !!

 

You will find that with those springs installed, you can run 15Wgt fork Oil, and NO air pressure. Ride will be great.

 

Also, install the " SuperBrace "

 

After you complete all this work you will find your bike drives MUCH Better, then with the Stock front end.

 

George,

 

Great minds think alike! :)

 

Already have the steering head bearing in hand, the Progressive are ready when things go back together, the 15wt fork oil is on the shelf and the SuperBrace clone has already been fitted.

 

As someone else mentioned (sorry, short term memory is lousy!) I'll be cannibalizing a set of MkI forks I picked up a while back. I'd really like to get this beast back on the road and get to chasing down whatever gremlins the PO has left for me!

 

Paul

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I just had the forks seals replaced on my 85 and was sad to discover how even with full air pressure the front ends still bottoming out. Reading about the difference between the stock and Progressive springs answers alot of my questions. Obviously the stock units are either weak and compress quickly with use or are just plain too short even with the air assist. It didn't help that the shop guys first ordered the wrong parts then took over a week to put them in. Needless to say I won't be going back there again. Looks like new Progressive front end is on my list of fixes.:)

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Don't sound right, even with OLD worn out springs. How many Miles on them ??

 

Usually 50K is about the lifetime limit for OEM springs.

 

Bye chance did they put 5 WGT Oil in there ?? Not good, should be 10 stock. I am running 15 Wgt. with new progressive, and Fine With -- NO -- air pressure.

 

Easy to Pop In the New Set of progressive Springs, and change to 15 Wgt. Oil.

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Tupper,

 

I was thinking, like others said, that you just didn't realize that the stock springs were shorter than the Progressives. Then I saw your pics! Those are some REALLY small springs, shorter than stock. Plus, stock are progressively wound, yours are not. And I though what you referred to as Conduit Spacers were really the stock metal tube spacers, and then I saw your forks had both! Somebody really conducted a parts experinet with your forks! Makes me think of that Johnny Cash song about the Caddy that was a model year 55-56-57-58...etc.

 

Jeremy

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Tupper,

 

I was thinking, like others said, that you just didn't realize that the stock springs were shorter than the Progressives. Then I saw your pics! Those are some REALLY small springs, shorter than stock. Plus, stock are progressively wound, yours are not. And I though what you referred to as Conduit Spacers were really the stock metal tube spacers, and then I saw your forks had both! Somebody really conducted a parts experinet with your forks! Makes me think of that Johnny Cash song about the Caddy that was a model year 55-56-57-58...etc.

 

Jeremy

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Tupper,

 

I was thinking, like others said, that you just didn't realize that the stock springs were shorter than the Progressives. Then I saw your pics! Those are some REALLY small springs, shorter than stock. Plus, stock are progressively wound, yours are not. And I though what you referred to as Conduit Spacers were really the stock metal tube spacers, and then I saw your forks had both! Somebody really conducted a parts experinet with your forks! Makes me think of that Johnny Cash song about the Caddy that was a model year 55-56-57-58...etc.

 

Jeremy

 

Jeremy,

 

Yep, I had quite the FrankenForks on the bike. Should be much better now, as I've scavenged some upper tubes from a MkI and put pretty much all new wear parts in the forks. When I broke down the MkI's I put the original equipment springs next to the mystery springs and the Progressives. Quite the stairstep!

 

Tomorrow, we seat the fork seals, new steering head bearings (AND RACES Dan! :)) and I should be good to go.

 

Well, good to go to find out why the bikes shuts down while riding, and why it doesn't want to restart. But that's another post. Or two!:whistling:

 

Thanks!

Paul

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