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Deerslayer
07-09-2003, 07:47 AM
What technique do you use in changing the fork oil?

On various bikes, I usually have simply removed the forks, opened the top and dumped the oil, pumping the fork assembly, rinsed with Varsol and left it hanging upside down overnight, then refilled with new oil - either using the amount stated in the Owners Manual or to the level previously measured prior to dumping the old oil. In the latter case, I put in oil, pump the assembly a bit, then re-measure the level and top up if necessary. Does that sound reasonable?

On my ZRX1100, there was a complicated disassembly specified in the shop manual, requiring a special tool, etc. (Those forks had compression and rebound damping adjustments as well as pre-load, so this is a more complex fork). Instead, I did what a friend of mine did, employing the technique described above. The quantity of oil used for the refill was less than the manual said - he had gotten that number from the dealer, I am not sure on what basis, but I have no reason to think there was anything wrong with doing it that way.

On my Yamaha TDR650, the manual specifies "284 ml" of fork oil. Absurd!
Even with a laboratory graduated cylinder, you won't get that kind of accuracy. You really have to wonder where they come up with such numbers!

The reason for asking is that I plan to do this myself in the Fall, before laying up my 2003 V-Strom for the winter. I believe that a fork oil change every couple years is ideal, but that the first year is the break-in year and it is important to do it then.

BTW, if you have never opened a fork which has fork oil that has been in there beyond its prime life-time, you are in for a surprise. It will be very obvious that you have waited too long. What a smell!

Opinions or advice?

scooter
12-12-2003, 12:52 PM
Stromies

Fork Oil

When should the fork oil be changed ( KM or Miles ). What is the original weight of the oil. How will the bike react with lighter or heavier oil. Considering to go to a heavier oil.

scooter

12-12-2003, 05:28 PM
Maybe there is an oil height measurement in the manual? Its much easier to drain them from the bottom, and then re-fill through the top, up to the correct height. I use one of those fancy syringes with the adjustable stop, it works great!

paul
12-12-2003, 08:58 PM
I just did my forks - I went to a 7.5 weight based on the recommendations that it would help ease the stiffness in the forks. This is probably better for road use that for off-road use. It did make the front forks a little softer. I haven't noticed any changes in performance - it still holds firm in corners. I took the forks off and drained the oil into a graduated measurement cup - then replaced the exact amount that I drained. Manual suggests changing fork fluid every 2 years (along with brake and clutch fluid). Hope that helps....

paul
12-12-2003, 09:00 PM
additionally - original weight of oil for 02's is 20 weight...

scooter
12-13-2003, 01:11 AM
Thanks Paul

Where ever I have read for a VS everyone seems to be going to a lighter

oil. I really do not know what the feel is with lighter or heavier fork oils on

this type of fork. I'am 240 lbs and I find the bike wallows when pushed

hard. I understand that this is put into the design of the bike. The rear

shock seems to be becoming more soft then the forks. Looking for a

cheap fix.


Scooter

paul
12-15-2003, 04:28 PM
Scooter - there were 3 cheap adjustments I made to the front end which made a world of difference - 1st was raising the forks in the triple clamps 1/2 inch, 2nd was putting a 7.5 weight oil in the forks, 3rd was tightening the steering head bearing. I have a little over 11,000 miles on my 02 - the last time I had the front wheel off the ground - I checked the steering head and could feel a noticeable play...