How To: Fork Oil Change

[Kurt'sSV]

Changing the oil in your stock SV forks to a heavier viscosity (15w, 20w, 25w, etc.) is a simple, cheap, and effective way to improving the action of your forks. It may seem like a pretty daunting task because there are a lot of steps to dismantling the front end of your bike, but once you do it, you realize you’re really just unbolting and rebolting pieces of aluminum.

The fastest way to change your fork oil is with a vacuum pump where you can leave the forks on the bike, remove all the internals, stick a long tube into the fork and suck out the oil, dump in new oil and then reinstall the fork internals and you’re done. Though, most of us don’t have a tool like that, so we need to take the fork off the bike and dump the oil out. To do that, read below.

Socket/Wrench sizes needed for 1st Gen SV650:
To remove forks:
19mm wrench
12mm socket/wrench
10mm socket/wrench* (*Estimated size, actual may differ)
8mm socket
6mm Allen head socket

To remove front wheel:
17mm socket/wrench
14mm socket/wrench
12mm socket/wrench

Socket/Wrench sizes needed for 2nd Gen SV650:
TBD

1. Lift front end of motorcycle off the ground either with a steering head stand (and rear stand) or suspend the front of the bike from above.

2. Loosen fork cap with 19mm wrench. It’s a lot easier to do this while the forks are still held by the triple clamps than simply by your left hand while your right hand is trying to turn the wrench.
- If your forks have pre-load adjustors, take all pre-load out of springs.

http://www.socalsvriders.org/albums/albvb75/Cap_Wrench.sized.jpg

3. Remove front wheel.

4. Use 8mm socket to remove front fender.

5. Use 10mm socket to unbolt clamp that routs your brake line and speedo wire down the fork tube.

6. Loosen lower triple pinch bolts with 12mm socket.

http://www.socalsvriders.org/albums/albvb75/Lower_Triple_Pinch_Bolts.jpg

7. For first Gen SVS, use 10mm* socket to unbolt clip-on from the under side of the upper triple.

8. Loosen upper triple pinch bolt with 6mm Allen head socket.

http://www.socalsvriders.org/albums/albvb75/Top_Triple_Pinch_Bolt.jpg

9. Pull out Forks.

10. Unscrew fork cap. Even with the pre-load adjusters turned all the way out, there is still some pressure put on the cap by the spring, so it will pop off a little bit once you get it all the way unthreaded. Just be aware.

11. Once you take cap off, on first Gen SV there is a washer under the cap that looks like a silver dollar. Take washer out. On second Gen SV, this washer is attached to the pre-load adjuster.

http://www.socalsvriders.org/albums/albvb75/Fork_Cap_Off.jpg

12. Take out spacer.

http://www.socalsvriders.org/albums/albvb75/Fork_Spacer.jpg

13. Take out fork spring.
When removing the spring, don't pull it straight up. "twirl" it out so the oil doesn't splatter all over the place (remember, the spring has been sitting in oil and will be drenched in it) - Stingray
(Note oil running down tripple and clip-on because I didn't "twirl" it - Kurt)
http://www.socalsvriders.org/albums/albvb75/Fork_Spring.jpg

14. Take out washer.

http://www.socalsvriders.org/albums/albvb75/Fork_Washer.jpg

15. Dump out old fork oil. Let the fork oil drain for a minute. Also, pump the fork to get all the oil pushed out from the damper rods. If your fork gets stuck in the compressed position, this is not unusual. It is hydro lock. Just pull on fork and it will pop open.

Sometimes, pulling on the fork tubes will not release them from hydro-lock. If so, slip the fork tubes back on the triple tree, tighten one or both upper and lower triple tree clamp bolts, and with a rubber mallet, give the bottom fork tubes a few whacks in a downward direction. The tubes should separate at that point. - harbiho

16. Refill fork with 450ml of new fork oil. You can add 10ml or 20ml more than that, just be sure to add the same amount to both forks. edit Or fill fork until oil is 120-115mm from the top while fork is compressed.

17. Reinstall fork internals: washer, spring, spacer, washer (on first Gen).

18. With fork extended, screw fork cap back on and torque to 16.5lb-ft (foot pounds). You’ll have to push the fork cap down on the spring fairly hard while pulling up on the fork tube so that it will thread in.

19. Slide fork back into triple clamps and tighten down pinch bolts. On both generation SV650 the torque spec for the upper and lower pinch bolts is 16.5lb-ft. The most important thing when tightening down the lower triple pinch bolts is that they are both tight. If you tighten one, then tighten the second more, the first one will be loose.

20. Repeat steps 6-19 for the other fork.

21. Reinstall front wheel and brakes.

22. Reset fork sag. You will need less preload on your forks now that you have thicker oil/more compression in your forks.

23. Ride bike.

[Apollo1777]

Very nice write up! Kudos! one thing that I did incorrectly, a very stupid mistake, is that I forgot to loosten the upper triple clamp and clip-on bolts that hold on to the top of the fork tubes BEFORE I tried to take that cap off. When I tried to take the cap off, I annoyingly ended up stripping the cap bold a little bit...

Also, I noticed in the pic that you marked the triple and the clip-on with a orange line to mark the position of the grips... Brilliant!! what did you use to do that (and does it wipe off? like a grease pencil?)?

[caslim]

Quick question, you state to add 450ml in each fork; however, the manual calls for 488ml in each. Do you put less in because of the thicker oil?

[racinteach]

best way is to measure from the top of the fork leg...should be anywhere from 120 -130 from the top..depending on your setup..this is with the fork leg compressed..

[Kurt'sSV]

Originally posted by caslim
Quick question, you state to add 450ml in each fork; however, the manual calls for 488ml in each. Do you put less in because of the thicker oil?

Hmm, that's a good question. I believe I came up with the 450 number per Zoran. 38ml isn't that much so I don't think you will feel much of a difference.

[SVNerd]

No - you don't put in more or less because of the oil's viscosity.

IMO - it really isn't the volume you should be measuring - but the "height" of the oil from the top edge of the tube, with the fork leg vertical, compressed, and all air bubbles purged. I usually use 115-120 mm as the reference distance.

I have yet to run into an SV650 fork that required more than 500ml for each leg, even with the lightest springs, and thinnest-walled spacer tubes.

[caslim]

Thanks guys for the input. Of course, I changed out my oil before I asked the question, so I have 450ml in each fork. I have stock springs, should I recheck the oil level?

[racinteach]

I would check oil level ...

[caslim]

Is there a way to check the fork oil while the forks are still on the bike?

[SVNerd]

Yes - take the caps off, carefully compress the fork(s) all the way (so as to not send oil everywhere ...). Measure the depth as vertically as you can acheive, from the forward edge(s) of the tube(s) - which should place your rule (or suction tool if you have one) at, or near the middle of the fork tube at the desired oil depth.

Don't worry - this approach will be close enough. A few ml or mm as the case may be, doesn't make any difference.

[caslim]

Okay, so to measure, you go from the top of the fork to the oil? And that should be about 115mm?

[Logans06SV]

where do you get a oil pump from?

[SVNerd]

RaceTech has a really neat one - pretty cheap too. It looks like a ball pump with a steel tube you can lock into place. Just set the tube such that the length exposed is equal to the height you want, using the top of the fork tube as a reference, just draw in the oil. Trival !

CycleGear or a stealer with a lot of tools might have them, or a like item.

caslim - approximately 115 to 120, try to get it the same in both forks.

[gothicbeast]

Originally posted by Apollo1777
Also, I noticed in the pic that you marked the triple and the clip-on with a orange line to mark the position of the grips... Brilliant!! what did you use to do that (and does it wipe off? like a grease pencil?)?

That is a racer trick :). Aftermarket bars don't have the pins to locate them like the stock SVS bars. I use a paint pen, but some people use a punch to mark a small dot on both the upper and the bar clamp.

I try to clamp my bar mounts as loose as possible to my fork tubes. I don't want to pinch them and if I crash I would like the bar mounts to rotate to put less load on the fork legs.

Post crash or after working on the bike, it is easy to locate the bars to the correct position. In addition when you keep the bars clamps a bit on the loose side, you can see if the bars shifted during a race :)

[pAint]

Originally posted by Logans06SV
where do you get a oil pump from?

Ghetto rig it.... get a tube, stick it in, and suck!

:D

[Sumo]

Originally posted by pAint
Ghetto rig it.... get a tube, stick it in, and suck!

:D

This explains sooooo much about pAint...



:D

[caslim]

okay. I checked the level and with fully compressed forks it's at 105mm from the top of the fork to the oil. Is this good, or should I take some out.

[SVNerd]

Take some out. 10-15 mm worth.

[caslim]

Okay. But why does the shop manual state 98mm (3.7 inches)?

[SVNerd]

As with any information presented on this site, you should proceed as you deem appropriate.

The information offered here is not merely experience derived, but also what aftermarket motorcycle suspension houses suggest. And that's all any of this is - suggestions on how to go about doing this. Regardless of what any of us try to assist you with, it should be clearly understood that you are proceeding at your own risk.