f4

Dealer. Belray.

i'm still new, how do you know if you need fork oil?

Mine needs fork oil and the way you tell is by pushing down on the handle bars. I can make my forks bottom out so I think I'm about out or oil. They shouldn't bottom out if the oil is full.

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Romeo,
The fork oil should be changed every year.
I use Belray 10 or 15 weight oil.
Cheers,
Todd

I thought it was every 2 years? I use motul 5w synthetic. Only because it's the only 5w my local stealership has. Note, I'm using the 5w with sonic springs, I wouldn't use 5w with stock springs.

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Fork oil should be changed every two years, per the GS500 maintenance schedule. I removed the forks to change mine, as it was simply easier. I got mine from a dirt bike dealer, went with 5W rather than 10W because of my springs, and got the super nice/expensive ($7/quart) Silkolene stuff.

I guess i found another thing that I'm going to have to fix before i can even think about riding my bike... i want to be safe before i go....

Motorcycle accessory shops may have better prices.  Since, I don't have the surgical feeling for my front end, I'll experiment with almost any brand of fork oil until I find the one I know I like; so far I've used BelRay 10w and am currently using Golden Spectro 5w.

What I do know, is that my forks feel better when I change the fork oil every other year. 

It's easy to remember, I just use what year the bike was made, '94, and remember to change it every even numbered year.

Here's my fork oil change method:
I always put a block under the engine, remove the front wheel, then use my handheld hammer-powered impact driver to loosen and remove the lower internal fork bolts.
After all the old oil drains out, I then pump the lower fork legs up and down individually on the fork tubes (which are still bolted to the front end) to get out the last of the old oil. I then reinstall and retighten the lower fork bolts, reinstall the front wheel and refill the forks with new fluid. Be sure to slowly pump the forks up and down after putting the new fluid in to get rid of air bubbles. Then install the springs and the top caps and button it all back up.
Always cover the fuel tank or remove it so you don't ding it!
No sweat and a huge difference in performance. I run Progressive springs inside the tubes.
I have a spare set of fork lowers and always fantasize about drilling a hole at the bottom on each side and tapping the holes for drain bolts. I miss when manufacturers still put drain bolts on fork legs! I still haven't tried my experiment. I wonder if you could braze or weld a nut on the outside of the fork leg and then use that to give solid threads for a drain bolt? Anyone want to try this and let the rest of us know? 

Good luck,
Todd
   

I did a How-To on removing your forks if you want to change your fork oil that way. For me, removing forks was easiest, and it allowed me to "pump" the extra fluid out.

http://gstwins.com/gsboard/index.php?topic=25706.0

nice write up, thanks.

I have a question. We all know that stock is soft. Can I firm them up by just using a different weight oil? or do I need to shell out for springs? I  just want to stop the nose diving. maybe feel the road a little better.

Quote from: dchrist on May 10, 2007, 06:02:35 PM
nice write up, thanks.

I have a question. We all know that stock is soft. Can I firm them up by just using a different weight oil? or do I need to shell out for springs? I  just want to stop the nose diving. maybe feel the road a little better.

The fork oil will only make a tiny difference, you really should go for new springs.

cool, thanks.

errr ... I got 10w from the dirtbike shop to go with my new  not-yet-installed .95 Sonics , as they said I probably misunderstood and meant 10 instead of 5 . Will it make much difference ?

I feel like I'm missing something here. I must be overlooking some painfully simple things. I'm new to bikes, but have lots of experience wrenching on cars. I've got a few questions concerning oil and preload in the front, and in reading this, other threads about it, AND my Clymer manual, I'm still 

Quote from: Trwhouse on May 10, 2007, 10:56:41 AM
Here's my fork oil change method:
I always put a block under the engine, remove the front wheel, then use my handheld hammer-powered impact driver to loosen and remove the lower internal fork bolts.
After all the old oil drains out, I then pump the lower fork legs up and down individually on the fork tubes (which are still bolted to the front end) to get out the last of the old oil. I then reinstall and retighten the lower fork bolts, reinstall the front wheel and refill the forks with new fluid.

Sounds great! Seems simpler than taking the forks off.  ....How exactly do I refill the forks with new fluid with your method?

Quote from: Alphamazing on May 10, 2007, 01:54:15 PM
I did a How-To on removing your forks if you want to change your fork oil that way. For me, removing forks was easiest, and it allowed me to "pump" the extra fluid out.

http://gstwins.com/gsboard/index.php?topic=25706.0

Looks like a good writeup, although Todd's method sure sounds easier. But let's say I get through yours. Now I get to this, "If your sag is not set in the area you want, pull the fork caps off and adjust preload accordingly. No need to take the forks out.". Again, the Clymer and searches on here aren't helping me. Am I turning something? Replacing shims? How is this adjusted?

Last question... I see plenty of people saying this here, but am I the only one that is not seeing in the maintenance schedule, on either the GS500 wiki or the Clymer, any mention of changing fork oil every 2 years? I feel like I'm going crazy!    I'm just trying to get this bike ready for a track weekend at the end of the month, and getting the proper amount of 15W oil in the front and adjusting the preload on both ends (I understand the rear adjustment) sounds like a good idea.

Thanks all, I've really appreciated a lot of the info on this forum so far, I hope to contribute something soon! 

nothing? I guess I'll just have to take them off and figure it out. After wrenching today though, I'm pretty unhappy with how frustrating this thing is to work on. Not looking forward to it.   

Yo ECPreston,
Sorry I haven't gotten back to you!
If you still need help, call me.
I just sent you my phone number by Personal Message.
The way to add fork oil is to pry the rubber caps off the top of the fork legs, then use a 1/2" drive rachet wrench extension to remove the fork upper caps.
BE SURE THAT YOU LOOSEN THE LOWER FORK BOLTS THAT GO INTO THE INNER FORK ROD BEFORE YOU LOOSEN THE CAPS, THOUGH, OR YOU WILL NEVER BE ABLE TO LOOSEN THE LOWER BOLTS! You will need to use that handheld impact driver tool I mentioned with the correct sized, long, allen head -- I believe it is 6mm or 8 mm. When you loosen these bolts, drop them out one at a time to drain the old fork oil out.
After all the oil drains, reinstall the lower fork bolt and tighten it securely again with the impact driver and a hammer. 
Once you loosen the lower bolts, drain the oil and reinstall the lower bolts, now you can remove the fork caps on top, which is where you will add the new oil.
Be sure to REMOVE the fork springs before filling the tubes with the new oil.
Then add the springs after adding the oil and reinstall the top fork caps, being careful to properly engage the very fine threads on the caps.
It's not as hard as it sounds.
Truly, call me on the phone if you need help.
Best wishes,
Todd