GStwin.com GS500 Message Forum

anyone here ever pull apart their fork leg to replace a fork seal? it all seems pretty simple by the service manual, but the first step is to loosen that allen screw right in the bottom of the fork, and supposedly the internal pressure from the springs is supposed to hold things tight enough to do it, but when i'm trying to loosen it, even with almost 100 pounds of pressure holding the fork compressed, i can still hear the insides twisting with it, my only other guess is to find a rather large bolt, and maybe an internally threaded rod to screw it into, just something that i can stick all the way down inside the fork into the peice that looks like a socket for a bolt, to hold it still, but i'm not sure, anyone have experience with this one?

Yes, the tool that you will need is as simple as going down to the hardware store and picking up a long  threaded rod and a few right sized nuts. Then all you have to do is tighten two nuts in opposing directions at each end of the rod to jam them against each other; this will prevent the nuts from roatating as you turn the  tool assembly.

AIR IMPACT!!!!
and
do not compress fork.....have someone try to pull it apart as you impact the allen bolt....two people tug-o-war with one impacting

oooh, pulling apart sounds good, i'll try that later, if not, zlei, do you remember what size nut i need to fit in there? it'd be easier than buying 6 of them just to see what size fits,

I don't know the exact size of the fitting on the GS500's dampening rod, but I did manage to come up with the following link after a little bit of searching.
http://www.gstwins.com/forum/viewtopic.php?t=7084

ooooh, zlei, that's awesome, i can never find that kinda stuff when i search for it, i'm gonna stop by lowes tomorrow and see what i can find, and i may look into the progressive fork springs, although it's not a necessity considering my budget, i know it'd make a huge difference on the handling, that and the huge flatspot from 5-6k rpm are my only real complaints about the bike, both i'd hope to have fixed someday

To remove the forks and refill them with new oil, etc. check http://www.bikepower.net => modification manuals => suspension related => progressive fork springs. It could be helpfull. Good luck!

i couldn't find a long enough bolt to just stick it in, so i did what that other guy did, and bought 2 10 inch bolts, and attached them with three nuts, and two locking washers, and it worked great, it came apart easier than i imagined after that, but the only thing i'm wondering now, is how do you put the oil seal back in? i know it just presses in, but i don't wanna damage it by trying to jam it back in with a screwdriver, i know what the real tool looks like, the peice that fits just on the outside of the fork rod so it pushes down on it evenly, but i don't have one of those,

will it be ok to just jam it in there as long as i'm careful, or is there something else i should try to do?

ooh, and incase anyone else has to do this, i got all the stuff i needed from lowes for $7.03,

I think you might be able to make a seal driver with some slightly over-sized piping from a hardware store. Just make sure it has enough mass to force the seal into position.

Quote from: tt_fouri did what that other guy did, and bought 2 10 inch bolts, and attached them with three nuts, and two locking washers, and it worked great

Couldn't find the coupler?  :roll:  Naw, I'm sure the nuts and lock washers worked great - no epoxy required.  Only, I wish I had bought two 9-inch bolts.  Did you find the combined 10-inchers to stick out of the forks a little more than necessary?

Quote from: tt_fourhow do you put the oil seal back in?

richard and I used a length of 1.5" Schedule 40 PVC pipe.  (Shown here with 20" tool in storage position.)


If you cut the pipe down like we did, make sure to put the "factory finished" end up against the seal.

EDIT: Changed link from sisna.com to bbburma.net

hmm....alright, i've gotta go up the street in the morning to buy new fork oil anyway, as well as some new motor oil, i'll take the old fork seal with me and get some pipe, hopefully they sell it in peices smaller than 8 foot long?? i'll throw the hacksaw and bungies in my trunk,

are the internals of most forks the same size? the gs has 37mm forks, but my triumph has 43, do you think i would be able to use the same tool i made to hold the insides still when i undo the bolt?

and kerry, no i couldn't, i looked, but if they had it, it was in a completely different section, but i had to get to work, so i didn't bother looking, i just grabbed the nuts and locking washers that were there, i knew i had jbweld here, so i was gonna glue it all together with that, but i tightened everything up just to give it a try, and it held up perfectly fine, so i didn't bother with the jb weld,


only other problem, is do any of you guys have the clymer service manual too? getting it apart was easy enough, and putting it back together should be fine if i just do it how it looks like i should, but it's one of those deals where it tells you how to take it apart, then in the instructions of how to put it back together, they all of a sudden had more parts to put back on that i started with, i was a little confused, but i'll see,

oooh, and i didn't check yet, i'm just asking cause i'm gonna go to bed, and when i wake up try to work on it, so i wont' have time to post and wait for a response if i need it in the morning, is there a good way to measure the fork oil? i'm gonna assume it just tells me how much to put in when i look in my manual, could i just buy a cheap measuring cup and do it that way? cause i'm sure the tool i saw in there costs more than it's worth

Measuring fork oil just by volume is kinda unreliable. But a ruler is all the special tooling you need to measure oil level. And some device to suck out oil (plastic squeeze bottle or suchlike.)

sounds simple enough, anyone remember off the top of their head how high up the oil is supposed to go?

From the Suzuki manual (1991 model, YMMV) 99 mm below the upper edge with springs removed and tube fully inserted.

For related info, read 4 posts (or so) starting HERE (http://www.gstwins.com/forum/viewtopic.php?p=62238#62238).

mark, thanks, i saw the 99mm in the manual, but when i measure that, you mean i should have the fork compressed, without the springs, and not stretched out, right? like as short as i can make it?

that should be the last question, thanks for all the help guys,


and just for refrence, if anyone goes to get pvc pipe at the hardware store, the one by my house only sells it in 10 foot chunks, so if you have a car, take that, cause i probably looked like a tool sitting in the parking lot with a hacksaw chopping that stuff up just so it would bungie to my back seat

Quote from: tt_four[...] i should have the fork compressed, without the springs, and not stretched out, right? like as short as i can make it?

Yep!  You got it.

Quote from: tt_fourif anyone goes to get pvc pipe at the hardware store, the one by my house only sells it in 10 foot chunks, so if you have a car, take that, cause i probably looked like a tool sitting in the parking lot with a hacksaw chopping that stuff up just so it would bungie to my back seat

:lol:

Good Luck, and let us know how it goes!

TT:

Pay attention to what your progressive spring directions tell you about fork oil level.  I've read the recommended 99mm between the oil surface and top of the fork tube, but the springs I got from Chaparral recommeded a MAXIMUM of 140mm which is a much larger air space, therefore more forgiving front suspension.

I'm glad I followed that advice or else my front forks would be very very stiff.  As of now they are perfect for me.  Not too hard, not too soft.  

Just my .02!   :thumb:

Thanks for the reminder.  I know that richard stuck with the 99 mm level even with his Progressive springs and 15-weight oil (and he likes the feel) but he weighs around ... 230 lbs?

I think I'll go somewhere in the middle if I ever get around to replacing my leaky fork seal and putting in new oil (with the Progressives which I already have).  Say, 120 mm for my 170 lbs?  I haven't decided on the fork oil weight yet....

it's mostly my girlfriend gs, and she's only like 120pounds, so i wouldn't wanna put too much in there, plus it's not like it's that hard to open them back up and dump a little more in, but either way, i'll just stick to the 99, cause i'm still using the stock springs, i'd someday like to go to the progressive ones, but as of my project this morning, it was just a new fork seal, hmm.....well they are pretty soft now, if i left the normal springs in, but put in a little more oil than the 99mm mark, would that help stiffen it at all? or should i just stick with the 99 and let it be?

My forks were stock for many many miles.  With your girlfriend's lighter weight, the 99mm should be fine.  That is, as fine as it can be without Progressives.  ;)

Quote from: stephanTT:

Pay attention to what your progressive spring directions tell you about fork oil level.  I've read the recommended 99mm between the oil surface and top of the fork tube, but the springs I got from Chaparral recommeded a MAXIMUM of 140mm which is a much larger air space, therefore more forgiving front suspension.

I'm glad I followed that advice or else my front forks would be very very stiff.  As of now they are perfect for me.  Not too hard, not too soft.  

Just my .02!   :thumb:

Makes sense. The progressives put more steel in there, so with the standard 99 mm there'd actually be a lot less air space. I guess the 140 mm put it back at about the same level when everything is installed.

I wrestled with getting the fork apart too. After lots of struggling I inserted a proper diameter short socket as a spacer in order to increase the spring tension. Then I hit the allen bolt with an impact gun. It worked great. Just a thought.