Front suspension options

[Audioslave784]

The front suspension on my 850L garbage. It's squirrely and a little scary over bumps, and it leaks fluid pretty badly. The PO had never taken care of the bike so I'm pretty sure the seals and everything else are original.

Here are the problems with my current set-up:
- Both fork seals leak
- Both tubes has rust specks/pitting all over the seal travel area

I want to upgrade to something decent. I don't need anything high-performance, but I want to make it comfortable and reliable. The problem is that I really don't have a lot of money to spend.

Here is what I would do if money wasn't an issue:
1. Leak-Proof Pro Moly Fork Seal - $36 at Dennis Kirk
2. Progressive springs - $82 at Dennis Kirk
3. New inner fork tubes - $260 from http://www.frankmain.qpg.com/
4. New fork oil - $10
Total: $388

I have 2 questions. First, what other options do I have in the $400 range? For example, are there decent used forks that I could pick up price range that would be compatible with my stock front-end components?

My second question is about a cheaper, temporary option. Might it be worth just sanding (and maybe filling in with JB weld?) the pitted spots and throwing in a cheap set of Parts Unlimited fork seals that I picked up a while back? This would be more or less free, but I would hate to spend the extra effort and additional bike down-time if it wouldn't get me safely and comfortably through the summer (probably ~1000 miles of riding). Of course I would eventually do the job right later on, after once again finding gainful employment.

What are your guys thoughts?

 

[posplayr]

The front suspension on my 850L garbage. It's squirrely and a little scary over bumps, and it leaks fluid pretty badly. The PO had never taken care of the bike so I'm pretty sure the seals and everything else are original.

Here are the problems with my current set-up:
- Both fork seals leak
- Both tubes has rust specks/pitting all over the seal travel area

I want to upgrade to something decent. I don't need anything high-performance, but I want to make it comfortable and reliable. The problem is that I really don't have a lot of money to spend.

Here is what I would do if money wasn't an issue:
1. Leak-Proof Pro Moly Fork Seal - $36 at Dennis Kirk
2. Progressive springs - $82 at Dennis Kirk
3. New inner fork tubes - $260 from http://www.frankmain.qpg.com/
4. New fork oil - $10
Total: $388

I have 2 questions. First, what other options do I have in the $400 range? For example, are there decent used forks that I could pick up price range that would be compatible with my stock front-end components?

My second question is about a cheaper, temporary option. Might it be worth just sanding (and maybe filling in with JB weld?) the pitted spots and throwing in a cheap set of Parts Unlimited fork seals that I picked up a while back? This would be more or less free, but I would hate to spend the extra effort and additional bike down-time if it wouldn't get me safely and comfortably through the summer (probably ~1000 miles of riding). Of course I would eventually do the job right later on, after once again finding gainful employment.

What are your guys thoughts?

another data point; Fast from Past added a line of fork tubes that are cheaper than Franks.
http://www.fastfromthepast.com/servlet/the-Fork-Tubes-cln-Suzuki/Categories


The repair to the forks you have all depends on how deep. I have used a buffer to "smooth" so rust specs. If it is smooth enough to avoid ripping the seal you are probably alright. If yoy have major rust grab a set from e-bay or go new with Fast from Past.

 

[Audioslave784]

Fast from the Past actually looks a little more expensive than Frank's. Their tubes are sold individually for around $140 while Frank's sells the pair for $260. Also Fast from the Past doesn't list fork tubes for any 850 models, although they have a huge selection so I'm sure that I could find one sized correctly.

I wouldn't call what I have "major rust"; the spots are numerous but small, although they are deep enough to easily feel with your finger. As long as people here don't think it's a terrible idea then I will probably just polish the spots, throw the cheap seals in, and cross my fingers. I don't have a buffing wheel, but how about wet-sanding the spots with 2000 grit paper followed by polishing compound applied by hand or a dremel tool? And is it advisable to use a little JB weld to fill in small pits?

 

[Steve]

I'm with Pos on this one.

Cleaning up your fork tubes will probably do the trick, then it's only springs, seals and oil, just $128.

If you wanted to save even more money, cut off a couple inches from each spring, add a PVC pipe spacer just a bit longer than what you cut off. That will raise the spring rate a bit and raise it back to proper height.

Fork oil: Mostly preference, but I have seen on some racing sites where they say "use the lightest oil that will do the job". This allows the suspension to move and do its job. I use 10w fork oil in all my bikes with good results. Had 15w in my Wing, but my wrists would hurt after a couple of hours from the constant impact of expansion joints on the road. Switched to 10w oil, now I can ride all day with no sore wrists.

.

 

[Steve]

I don't have a buffing wheel, but how about wet-sanding the spots with 2000 grit paper followed by polishing compound applied by hand or a dremel tool? And is it advisable to use a little JB weld to fill in small pits?

The 2000 paper might not do what you need, at least not to start with.
Might try some fine emory cloth or even some LIGHT touches with a very fine file to take off the high points.
I think I have even heard of using a whetstone (used for sharpening knives) to polish the high spots down.
THEN you can break out the 2000-grit to polish it up.

.

 

[mike_of_bbg]

My understanding is that you have to REALLY degrease your forks well if you want JB weld (or any other epoxy) to stick. I started and finished with some 600 grit on mine (no epoxy); small light swirls over the spots until there were no high lips, then a circumferential cleaning pass or three.

 

[bwringer]

Very hard to tell without seeing the pitting and how much of it is in the seal area.

I don't really see why JB Weld is needed -- the problem is not so much the pits, it's the sharp edges of the pits that quickly destroy new seals. If you can get the surface pretty smooth, the Leak Proof Pro Moly seals will work surprisingly well. I've used a polishing wheel to dress pitted forks with excellent results.

Or, it would probably be best to just scare up a used set of forks in better shape. There are skrillions of GS850GL, GS1000GL, and 1100GL bikes out there with the same forks. Shouldn't be very hard to find a decent set to rebuild.

Also, you may want to add to your list the bushings inside the forks. It's optional -- these last virtually forever, but the manual says to replace them. They called "SLIDE METALS" on the diagrams for some reason.

I would also order up new damper rod bolts and the copper sealing washers. These use an oddball thread, and quite often get destroyed or damaged when you remove them. The other item I would add are new spring clips (the ones above the seals) -- these often get rusty and fail, and in fact rust chips from corroded spring clips are a leading cause of fork leaks.

The other thing to remember is that you CANNOT pound in Pro Moly seals like regular seals or they will get damaged and leak. You must gently massage them in with your fingers and maybe a blunt plastic tool, preferably while whispering soothing words. Maybe play a little Barry White on the garage stereo.

 

[posplayr]

The other thing to remember is that you CANNOT pound in Pro Moly seals like regular seals or they will get damaged and leak. You must gently massage them in with your fingers and maybe a blunt plastic tool, preferably while whispering soothing words. Maybe play a little Barry White on the garage stereo.

Do we need to turn you in for brutalizing some Moly Seals?

How many sets? Come on fess up.


I went through three ignition crank seals to get one in (at $11 a pop ). (OK See I confessed)

 

[twr1776]

#7 Yesterday, 10:46 PM bwringer The other thing to remember is that you CANNOT pound in Pro Moly seals like regular seals or they will get damaged and leak. You must gently massage them in with your fingers and maybe a blunt plastic tool, preferably while whispering soothing words. Maybe play a little Barry White on the garage stereo.

I saw this done once in my garage and it is not for the faint of heart.

I can't remember if Barry was on the radio at that time, or not. :-\\\

 

[Audioslave784]

Thanks for the help so far guys! It's great to hear that I don't need to drop $80 on progressive springs, just $3 on some Schedule 80 PVC (although this was a PIA to find). I'll be sure to use a gentle touch with my seals

As of now I've got the forks off the bike and the springs out, and I'm waiting for my JB-welded rod-with-a-nut-on-it tool to dry. These forks were critically low on oil; one had enough to fill the cap of a spray paint can (the best measuring tool I had available), and the other had NONE. No oil, save a few drops. I am slightly horrified that I've been riding this machine on the highway.

Unfortunately the decision about whether to get new fork tubes was made for me, as one of the tubes is binding badly and I'm guessing it's bent.

I do plan to buy used, though. How do I tell which other GS forks are compatible with my bike. I know the 850 L tubes are longer than the regular 850 ones; I also know that the only other bike using the same tube part number is the '79 1000 GL.

Is fork compatibility simply a matter of matching the tube length and diameter? What about fitting tires and brakes? I found some decent looking '79 1000 L forks on Ebay for $90 shipped; is this a fair price, and will my tires and brakes fit normally?

http://cgi.ebay.com/ebaymotors/1979...2265725QQptZMotorcyclesQ5fPartsQ5fAccessories

 

[BassCliff]

Hi,

Schedule 80 PVC pipe is pretty flimsy. I used schedule 40 in mine. Actually, my Progressive springs came with a length of schedule 40 PVC. See the "Install Progressive Fork Springs" guide on my website for details. It shows how to set the "sag", etc.

If those forks are in good shape, I would pay that price if I needed them. The PO of my bike bought fork tubes from Forking by Frank and paid hundreds of dollars for them.


Thank you for your indulgence,

BassCliff

 

[Audioslave784]

Hi,

Schedule 80 PVC pipe is pretty flimsy. I used schedule 40 in mine. Actually, my Progressive springs came with a length of schedule 40 PVC. See the "Install Progressive Fork Springs" guide on my website for details. It shows how to set the "sag", etc.

If those forks are in good shape, I would pay that price if I needed them. The PO of my bike bought fork tubes from Forking by Frank and paid hundreds of dollars for them.


Thank you for your indulgence,

BassCliff

I thought schedule 80 was the stronger stuff? Good to know that regular sch 40 will work.

I have been using both the progressive spring installation guide and the fork seal guide for taking apart the forks. Using both gives double the pictures - great for a first-timer

Before I order these new forks, could somebody confirm whether the '79 1000 L lowers are compatible with the '80 850 L wheels and brakes? The fork lowers and wheels have different part numbers between the models, how can I tell if they are compatible?

Edit: I'm actually starting a new thread on my fork compatibility question.

 

[BassCliff]

I thought schedule 80 was the stronger stuff? Good to know that regular sch 40 will work.

Hi,

You know, I'm looking at PVC pipe specs right now and I may be confused. (Imagine that? )

http://www.harvel.com/tech-specs-pvc-pipe-40.asp
http://www.harvel.com/tech-specs-pvc-pipe-80.asp
http://www.harvel.com/tech-specs-pvc-pipe-120.asp


Thank you for your indulgence,

BassCliff

 

[scrapper]

try looking on bike bandit at the fich. they list most all the part numbers. You could try listing on need to buy on this site,and for sell, alot of people list parts bikes.

 

[Guest]

I have forks from a 79 "N" $50.00, missing 1 damper rod bolt.

Toddk

 

[dcil]

I used steel wool and some wd40 on my fork rust. gone in seconds. they looked really bad until I did it.

 

[Audioslave784]

I have forks from a 79 "N" $50.00, missing 1 damper rod bolt.

Toddk

Thanks for the offer, missing parts are not a problem as I have plenty of good internals. Unfortunately I need longer leading "L" forks.

Just picked up the '79 1000L forks off Ebay for $90. Hopefully there are no length or fitment problem. Will keep you all posted.