Simple Fork Questions From a Newbie

[calee4nyaboy]

Hi All,

I am the happy new owner of a 1980 GS1000/G. Since I was not sure of the condition of the front forks and for the fact that the front brake rotors were gummed up with stuff, I decided to rebuild the front forks to be sure.

After removing the forks, I ran into a couple things that I wasn't sure about so I thought it was best to ask the experts here:

1) The springs that came out were progressively wound. Aren't the factory springs NOT progressively wound? Are these after-market springs that a prior owner put in?

2) I have removed the snap ring holding in the oil seal but when I try to gently (or not so gently) pry the seal out, the darn thing won't budge a millimeter. How do you get the oil seals out?

3) The fork leg had 200ml of oil in it when I disassembled it. Isn't that low?

4) When you put oil back in, the manual says to take the spring out and compress the fork. It says put it to 140mm. Is this measuring 140mm from the BOTTOM OF THE FORK UP TO 140mm (kind of like measuring on a dip stick in car) or from the TOP OF THE FORK TUBE MEASURING DOWN 140mm UNTIL YOU HIT THE HIGH POINT OF THE FLUID? Can't believe the manual doesn't specify this, at least on page 10-10 it doesn't.

5) The oil that came out of it was black, like used motor oil. Is that normal? I have never bought this kind of oil before so I didn't know what color it should be but I figured black was not a good thing...lol

6) Speaking of buying it, what's the best kind of oil for forks and where do you buy it. Anyone use Synthetic fork oil? (is there such a thing?)

7) This question is a little off subject (and probably sounds really dumb) but this is my first bike and I can't figure out how to use the center kick stand? I only weigh 140 lbs so this bike is very heavy (~1150 lbs) for me to move around but when I try to get the bike up on the center stand, it just doesn?t wanna go. Is there a trick?

Sorry for all these dumb little questions but I just wanna get the forks running really well. I'm excited about the bike and knowing there is actually a group of people out there that like these things as much as me.

I moved to Columbia, SC so if there is anyone close to me that may want to work on these beasts, together drop me a note.

Thanks guys!
John

 

[t3rmin]

In reply to the center stand thing: it's all technique. My buddy was complaining about how hard it was to get his heavy bike on the center stand, and when I said "let me try" he gave me a knowing smirk but wiped it off immediately when I swung it up on the stand easy as pie. ;-)

Of course when I first bought my bike and didn't know the technique it took me 15min and a lot of sweat and determination to get it on the centerstand. And I've only got a 650! ;-)

Put your left hand on the left handlegrip and grab the seat rail or rear frame with your right hand (not too far back, make it straight up from where the centerstand is). Then push down on the centerstand with your left foot until you can feel the bike is straight up and down and both sides of the stand are firmly on the ground. Then just step on the centerstand ear with all your weight and at the same time pull straight up with your right hand on the frame/grab rail. It'll pop right up.

 

[calee4nyaboy]

Oh, when I tried the center stand, I was standing over the bike (over the seat) and yanking back on the bike while trying to get the stand to prop. I didn't wanna stand next to the bike because I was afraid it would fall over if I lost it's balance.

I did want to clarify about the springs that came out of the forks when I took them apart. Most progressive springs I have seen had a CONTINUOSLY changing coiling from one end to the other. These, however, have two different coil rates. It's coiled tightly at one end and on up to the middle. Then at the middle it suddently changes to a more open coil all the way to the opposite end. Does that sound like stock?

 

[Guest]

The springs are progressively wound.
My oil seals were stuck good, too. I ended up cutting a notch with side cutters onto the rubber portion, bending the seal into the center, then cutting the metal portion, then "peeling" them out. I'm sure there's a better way, but that's how I did it. Make sure the side walls and base are clean and smooth before you put the new ones in.
Yes, the oil was low. Your bike shows needing 260mm per leg.
The measurement is from the top of the fork... 140mm of empty tube.
I use Belray 15W fork oil. When new it looks kinda green. Yours was dirty.

The center stand takes some practice. Do a search... there are some good threads on the subject.

 

[louisciccoli]

I reciently replaced the springs & oil seals in mine & the one was a real bear to remove. I used a pulley puller with a single hook & a slide hammer to remove them. The first one came out fairly easily, but the second fell apart before it finally decided to come out. And as far as synthetic oil, I replaced the black, burnt oil (I think it was original ! ) with the synthetic. I went with a straight 20 weight oil, but you may want to go with a lighter weight being I weigh in @ about 215 lbs. Just my thoughts.

 

[beby99]

Oh, when I tried the center stand, I was standing over the bike (over the seat) and yanking back on the bike while trying to get the stand to prop. I didn't wanna stand next to the bike because I was afraid it would fall over if I lost it's balance.

Oh, you can do it that way....but it will take a different technique and long legs.

 

[mark]

2) I have removed the snap ring holding in the oil seal but when I try to gently (or not so gently) pry the seal out, the darn thing won't budge a millimeter. How do you get the oil seals out?

4) When you put oil back in, the manual says to take the spring out and compress the fork. It says put it to 140mm. Is this measuring 140mm from the BOTTOM OF THE FORK UP TO 140mm (kind of like measuring on a dip stick in car) or from the TOP OF THE FORK TUBE MEASURING DOWN 140mm UNTIL YOU HIT THE HIGH POINT OF THE FLUID? Can't believe the manual doesn't specify this, at least on page 10-10 it doesn't.

I've got a pry bar with a long handle on it that I use to pop my my seals out. But don't pry against your outer tube directly, to avoid damage use a small piece of 1/4'' plywood or something similar.

My specs just call for removing the spring, fully compressing the tube, adding oil, then pumping your fork up and down a few times. Should be good enough. You should have a spec. that simply calls for the amount of oil to put in.

 

[calee4nyaboy]

My specs just call for removing the spring, fully compressing the tube, adding oil, then pumping your fork up and down a few times. Should be good enough. You should have a spec. that simply calls for the amount of oil to put in.

I have heard that its not actually about the amount of oil you put in but the level to which it goes to. So if you have progressive springs, which take up a different amount of volume in the fork than factory springs, the factory oil amount may not bring you to 140mm (it may be more, or it may be less). So my question is, if you have to add the oil with the non-factory spring out, how do you know whether the level is right when you drop the spring back in?

As for maintanence, the insides are a bit dirty and I'm wondering the best way to clean them out. It's kinda hard because they are so long that you can't really get to the all insides that way. Can I use gas to break up the bad oil and dirt, clean them out real well, then rinse them out to remove any gas remnents, let dry, then add new oil?

John

 

[Road_Clam]

Hi All,

I am the happy new owner of a 1980 GS1000/G. Since I was not sure of the condition of the front forks and for the fact that the front brake rotors were gummed up with stuff, I decided to rebuild the front forks to be sure.

After removing the forks, I ran into a couple things that I wasn't sure about so I thought it was best to ask the experts here:

1) The springs that came out were progressively wound. Aren't the factory springs NOT progressively wound? Are these after-market springs that a prior owner put in?

2) I have removed the snap ring holding in the oil seal but when I try to gently (or not so gently) pry the seal out, the darn thing won't budge a millimeter. How do you get the oil seals out?

3) The fork leg had 200ml of oil in it when I disassembled it. Isn't that low?

4) When you put oil back in, the manual says to take the spring out and compress the fork. It says put it to 140mm. Is this measuring 140mm from the BOTTOM OF THE FORK UP TO 140mm (kind of like measuring on a dip stick in car) or from the TOP OF THE FORK TUBE MEASURING DOWN 140mm UNTIL YOU HIT THE HIGH POINT OF THE FLUID? Can't believe the manual doesn't specify this, at least on page 10-10 it doesn't.

5) The oil that came out of it was black, like used motor oil. Is that normal? I have never bought this kind of oil before so I didn't know what color it should be but I figured black was not a good thing...lol

6) Speaking of buying it, what's the best kind of oil for forks and where do you buy it. Anyone use Synthetic fork oil? (is there such a thing?)

7) This question is a little off subject (and probably sounds really dumb) but this is my first bike and I can't figure out how to use the center kick stand? I only weigh 140 lbs so this bike is very heavy (~1150 lbs) for me to move around but when I try to get the bike up on the center stand, it just doesn’t wanna go. Is there a trick?

Sorry for all these dumb little questions but I just wanna get the forks running really well. I'm excited about the bike and knowing there is actually a group of people out there that like these things as much as me.

I moved to Columbia, SC so if there is anyone close to me that may want to work on these beasts, together drop me a note.

Thanks guys!
John

It's NOT a good idea to pry the seals out. They are a tight press fit down inside the outer tube. You seriously risk gouging the inner tube. If this happens, you are SCREWED, as the inner tube will quickly tear the new seal. The correct way to remove fork seals is to remove the bolt down inside the tube (you need an impact gun. Once that bolt is removed, you compress, and briskly "snap" the inner tube out (like a slidehammer effect). The inner bushing pushes the seal right out. Any dealer can do this, it takes about 10 min to do. To replace the seals, there is a special heavy "bushing/seal installer that you simply slide down the inner tube, and bash the new seal into the bore.

A tip, it's a great way to prevent rust pits on your fork tubes, by dabbing a small amount of oil on the inner tubes like every other month. This is especially advantagious to bikes here in New England, that sit in a cold garage for 4 months.

 

[Guest]

I would use kerosene to clean them out.

The important part of adding the oil would be to get equal amounts in each leg. I have seen posts that say the amount is not important, the level is. But I would think adding equal amounts in each leg to a clean, empty fork will give you the same level in each leg. I didn't check the level when I rebuilt my forks. I add the exact same amount in each leg. That should be close enough. Plus I went off an old article that showed if I put Progressive Springs in, I could bump the oil amount up to 260cc (the stock 1000E gets 241cc) and eliminate the need for air. My front suspension is nice and firm.

 

[Guest]

To replace the seals, there is a special heavy "bushing/seal installer that you simply slide down the inner tube, and bash the new seal into the bore.

A piece of 1 1/2" PVC works great, too.

 

[mark]

It's NOT a good idea to pry the seals out. They are a tight press fit down inside the outer tube. You seriously risk gouging the inner tube. If this happens, you are SCREWED, as the inner tube will quickly tear the new seal. The correct way to remove fork seals is to remove the bolt down inside the tube (you need an impact gun. Once that bolt is removed, you compress, and briskly "snap" the inner tube out (like a slidehammer effect). The inner bushing pushes the seal right out. Any dealer can do this, it takes about 10 min to do. To replace the seals, there is a special heavy "bushing/seal installer that you simply slide down the inner tube, and bash the new seal into the bore.

I've always pryed mine out, but not with the inner fork tube still attached of course :smile: , but after dissassembly. I would be interested however in learning more about the method you describe.

Also an impact gun isn't needed to take the bottom bolt out, I have the correct bolt with the same sized nut torqued on with a lock-washer that I can slide in there attached to a socket and long extention on to get the bolt out. Maybe my bike is different.