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Main Area => General GS500 Discussion => Topic started by: Nomak on July 21, 2005, 12:27:57 PM

Title: Fork Oil ...
Post by: Nomak on July 21, 2005, 12:27:57 PM
what weight fork oil do you use with progressive springs?  I changed the fork seals and put in 10wt and the forks were stiff as hell would hardly budge ... cause me to wipe out ... I got new forks on the way and will be changing the seals again what are your recommendations?
Title: Fork Oil ...
Post by: Jazzzzz on July 21, 2005, 01:36:32 PM
lots of people go up to 15wt with progressive springs, but you can stick with 10wt or even go down to 5, whatever works for you.  I prefer the 15wt myself, but I weigh around 185.

Did your forks not have enough travel/lock up on you?  Might have put too much oil in the forks when you swapped your springs or redid the seals.
Title: Fork Oil ...
Post by: StevenE on July 21, 2005, 02:32:57 PM
Standard is 10W I think. Adding thicker oil will give you more damping. That's an easy mod to add more damping, unless you race on the track.

The thicker the oil, the lesser it will withstand heat. And there is a lot of heat generated in your forks on the track. But then again, if you are racing, you probably already installed the cartridge emulator by Race Tech. I hear it's great stuff.
Title: Re: Fork Oil ...
Post by: mjm on July 21, 2005, 03:17:23 PM
Quote from: Nomakwhat weight fork oil do you use with progressive springs?  I changed the fork seals and put in 10wt and the forks were stiff as hell would hardly budge ... cause me to wipe out ... I got new forks on the way and will be changing the seals again what are your recommendations?

you put in TOO MUCH OIL or TOO MUCH PRELOAD or both
Title: Re: Fork Oil ...
Post by: Lukewarm Wilson on July 21, 2005, 04:04:06 PM
Quote from: mjm

you put in TOO MUCH OIL or TOO MUCH PRELOAD or both
_____________________________________________________________
If your short on size and weight use 10wt and cut your spacers to half the recommended length you'll be right if these don't work you've got way too much oil in there :thumb:  :cheers:
Title: Fork Oil ...
Post by: Nomak on July 21, 2005, 07:18:39 PM
I think I put too much oil
Title: Fork Oil ...
Post by: number1 on July 21, 2005, 10:27:07 PM
so how much are you suppossed to put in.
Title: Fork Oil ...
Post by: Lukewarm Wilson on July 21, 2005, 10:47:40 PM
I think by memory ( hope i'm right) about 130ml in each leg hopefully someone will back me up or prove me wrong :thumb:  :cheers:
Title: Fork Oil ...
Post by: Faxxxy on July 22, 2005, 02:03:52 AM
Quick thread-jack here..
Is fork oil its own thing, or are you guys putting motor oil in your forks?

My forks are in the back of my truck because I could not figure out how to get the failing seals out of them. I figured I was going to take them to the shop and have them done..
Title: Fork Oil ...
Post by: Jazzzzz on July 22, 2005, 02:19:33 AM
fork oil is its own thing, should be available at any motorcycle dealer in the parts dept. along with the chain lubes and other various and sundry goodies
Title: Fork Oil ...
Post by: Nomak on July 24, 2005, 08:43:29 PM
the manual says ... 382 ml or 12.9 US oz... I think the prob was that I eyeballed 13 OZs ... the dood I bought my forks from had 1.25" spacers in the forks I rode them like that for a good 5xxx miles and it felt fine ... after the seal and oil change since the forks didnt budge at all I didnt put the spacers/preload back in but even after that the forks would hardly compress ... well this time I shall measure it properly ... wish me luck this is my third set of forks on this bike ... man my crash ratio sux  :lol:
Title: Fork Oil ...
Post by: Jace009gs on July 24, 2005, 09:01:17 PM
I'm not sure on the manual's suggested amount of oil but 12.xx something sounds like a little much for me when I did my forks/seals. The manual gave a ball park figure as that is good enough because I'm sure the 12oz is completely bone dry. If you put the seals in, spacer in, spring in and pull the tube up there should be 3" of space where the ruler doesn't get in the oil.....kinda of the same thing as a dipstick for forks...

I will double check the 3" and edit my post as soon as I find out what page I read that on...note to self highlight that for future use.
Title: Fork Oil ...
Post by: scratch on July 25, 2005, 08:22:25 AM
377ml to 382ml, if you are using that method of measuring your fork oil. I don't remember what the measurement is for measuring the level.

Progressive suggests .75 inch preload spacers. This would be good if you're over 130lbs and/or an aggressive rider.

Best to set your sag, with you aboard in full riding gear, to 1.5 inches. Sometimes it can be difficult to set your sag properly and accurately with only a solid spacer; I use 1/8" thick washers from Orchard Supply.
Title: Fork Oil ...
Post by: Nomak on July 25, 2005, 09:17:59 AM
intially I dont think Imma put in any preload at all ... I m a fairly agressive rider and weigh bout 160lbs ... how much fork oil is recommended if the manual is incorrect? Ill make some preload later

(http://img.photobucket.com/albums/v56/ngpatel/jgp1.jpg)
Title: Fork Oil ...
Post by: scratch on July 25, 2005, 09:22:43 AM
The manual is correct. 377ml is a suggestion for the stock springs. 382mls is the correct amount for, again, stock springs as stated in the manual.

I have measured 350ml when I put in Progressive springs.

So be careful, if you put in over 350mls in with Progressive springs you will definitely suffer a stiffer ride, most likely from hydraulic lock.
Title: Fork Oil ...
Post by: Blueknyt on July 25, 2005, 10:51:35 PM
said it before, Ive read in a few forums and talked to a former racer/Motorcycle shop (mechanic) a few times, he claims if your running specially valved forks or special race forks then put in the amount they specificly say. IF however your running mostly stock NON adjustable dampening forks, compress the fork tube into the leg with the spring installed and add till the level is about 6 inches from the top of the tube. you can vary the dampening with the diff weights of oil.  ive got progressives and Emulators in mine, and im a heavy dude. ive never adjusted the emulators as previous rider was slightly lighter then me. but i went to a heavier oil cuz i like a ride with a lot of feed back and stiff suspention.  

ive changed forkseals in a few bikes and have use the same oil fill methode. seems to work well for me. ive still got some oil left over from completing the katana forks this past weekend (yeah forgot to take my camera to work with me for a writeup, but i still have my spare GS front end to do yet)
Title: Fork Oil ...
Post by: Faxxxy on July 26, 2005, 04:00:35 AM
I gave up..
My forks are in the back of my truck and they are going to the shop to have the seals replaced..

I have jerked, pulled, and even hammered on them with a rubber mallet..
Those fork seals are not coming out..

I just hope they can get me done quick and cheap..
Title: Fork Oil ...
Post by: Jazzzzz on July 26, 2005, 04:18:13 AM
Quote from: BlueknytIF however your running mostly stock NON adjustable dampening forks, compress the fork tube into the leg with the spring installed and add till the level is about 6 inches from the top of the tube.

the installation manual that comes with Progressive Suspension's progressive springs says to measure the fork oil with the fork collapsed and no springs installed - likely because their springs are long enough that they would stick out far past the end of the tubes once the tubes are collapsed.

140mm of oil, as suggested by the Progressive guys, measures out to just a hair over 5.5 inches.  I installed my springs yesterday via Pantablo's method and measured the fork oil by depth rather than volume, since I didn't have a large syringe to use for adding the new oil.  I haven't ridden the bike yet since I'm working on a few other items too (repainting my exhaust and changing my footpegs) but I set the sag and bounced the forks quite a bit, etc.  The response seems much better, with no lockup and a good stiff feel.  There is a downside though - the progressives are noisy; stock springs were totally silent, these squeak a bit (I installed them with the tightly-wound side down as recommended to control noise).
Title: Fork Oil ...
Post by: Nomak on July 26, 2005, 09:00:01 AM
Jazz, I dont know wot brand my springs are but they are progressives (ie type) did you put any preload?

Quote from: scratchThe manual is correct. 377ml is a suggestion for the stock springs. 382mls is the correct amount for, again, stock springs as stated in the manual.

I have measured 350ml when I put in Progressive springs.

So be careful, if you put in over 350mls in with Progressive springs you will definitely suffer a stiffer ride, most likely from hydraulic lock.

how much do you weigh? how do the forks "feel"? ...
Title: Fork Oil ...
Post by: Jazzzzz on July 26, 2005, 09:29:49 AM
I put in 1" of preload - I weight about 185 in full gear.  I used 15wt oil.

The forks are smooth - they compress quickly for the first couple of inches and then stiffen up noticeably.  As I said, I have not had a chance to ride the bike yet, so I can't really comment on diving during hard braking, big bumps, etc. yet - I'll find out tonight once I get my exhaust painted and put back on, along with my new pegs.
Title: Fork Oil ...
Post by: Nomak on July 26, 2005, 02:31:06 PM
I weigh about 160 lbs I dont plan on puttin any preload atleast not immediately so do I put in 140 ml or 350ml? thats a big discrepancy in the 2 suggested volumes
Title: Fork Oil ...
Post by: Jazzzzz on July 26, 2005, 02:53:51 PM
140mm, not ml - 140mm is the distance from the top of the fork to the level of the oil when the fork is collapsed and has no springs/spacers in it
Title: Fork Oil ...
Post by: Kerry on July 26, 2005, 10:40:08 PM
Quote from: FaxxxyI gave up.. [...] I have jerked, pulled, and even hammered on them with a rubber mallet..
Those fork seals are not coming out..
Did you ever undo the bolt at the bottom end of the forks?  That's got to come out before the sliders will pull free, bringing the seals along with them.

Check out this thread to experience the initial frustrations, and then final successes, of others.  And the variations on a cool homemade tool that made it possible.  :thumb:
Title: Fork Oil ...
Post by: Nomak on July 27, 2005, 08:04:46 AM
Quote from: Jazzzzz140mm, not ml - 140mm is the distance from the top of the fork to the level of the oil when the fork is collapsed and has no springs/spacers in it

oh ok so I guess I'll go with 350ml then
Title: Fork Oil ...
Post by: Faxxxy on July 27, 2005, 08:12:12 AM
Quote from: Kerry
Quote from: FaxxxyI gave up.. [...] I have jerked, pulled, and even hammered on them with a rubber mallet..
Those fork seals are not coming out..
Did you ever undo the bolt at the bottom end of the forks?  That's got to come out before the sliders will pull free, bringing the seals along with them.

Check out this thread to experience the initial frustrations, and then final successes, of others.  And the variations on a cool homemade tool that made it possible.  :thumb:

Well now..
Thats something I hadn't read about..

I filled the forks with used motor oil and was trying to compress them and blow the seals out...

I wasn't having any luck..
Title: Fork Oil ...
Post by: manofthefield on July 28, 2005, 07:15:33 PM
Stupid question: Is it 350ml(or 380 or...) per fork?  If so I need to go buy another bottle of fork oil...
Title: Fork Oil ...
Post by: scratch on July 29, 2005, 08:08:52 AM
Yes.
Title: Fork Oil ...
Post by: Nomak on July 29, 2005, 09:41:03 AM
Quote from: manofthefieldStupid question: Is it 350ml(or 380 or...) per fork?  If so I need to go buy another bottle of fork oil...

350 ml/fork is if you have progressive spings its 382 ml with stock factory springs (Clymer Manual)