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fork oil


scott s.

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What are the service intervals for changing the fork oil? I'm sure I'm overdue by now.

Also, if I were to just change the oil, what's the easiest way to drain the fork tubes? I never noticed a drain screw. I guess I would have to pull the front wheel, and remove the center allen bolt that runs up the middle of the fork tube via the saddle in the leg that the axle sits in.

Any other ideas?

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I just removed the factory fork oil at 65k miles with my Hyperpro install.

I expected the stuff to be black. It came out looking brand new!

As much of a maint. freak as I am, fork oil is the one thing I slacked on. Now I don't feel so bad about it.

The Hyperpro oil might be in there a long time to come.

The correct way to service our forks is to remove them and turn upside down to drain. Hardest part is securing the bike so the front wheel is off the ground.

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can you use a fork oil guage to suck out the oil?

The proper way is to bite the bullet and remove the forks. Doing so is considerd an ass-pain to some, but it's the way to go if you care about doing the shit right, getting a thorough, proper drain. You can, if you want to, opt for leaving them in place and draining them via a cartrige retaining bolt at the very bottom of the fork leg. It's an option, though I personally don't recommend it.

After you remove the fork off the bike, thoroughly clean that slider tube since you'll be pumping the fork leg quite a bit during this exercise, and you don't want any crusty bugs or other debris to dork up your fork seals as you work the forks:

CleanTube.jpg

Hopefully you remembered to loosen the 24mm top cap prior to removing the fork from the bike:

24mmTopNut.jpg

After the fork is removed and the 24mm top cap loosened, you can pull down the spacer tube to expose the 14mm locking nut. You (obviously) need to hold the top cap with the socket while you take a 14mm wrench to loosen the locking nut:

14mmDamperNut.jpg

Now that the top cap is removed, you can remove the long spacer tube:

Spacer_Tube1.jpg

And pour out that nasty-ass old fork fluid (pour it in a measuring device if you want to know the exact amount of fluid you removed):

DrainForkFluid.jpg

After the tube is close to being upside-down, get ready to catch the spacer ring and fork spring and they emerge from the slider tube. Pump the tube (and the damper rod) many, many times to try to get every last drop out that's going to come out. Some guys hang their forks upside down overnight (over a container, obviously) to get a uber-thorough fork oil drain:

FinalDrain.jpg

As you can see, I only got about 15oz of fork oil out this fork:

FluidLevel.jpg

Basically, the procedure for obtaining the 150mm air gap height is to dump around ~375mm of fluid in the collapsed fork leg, reach in and pull the damper rod, and pump the damper rod up and down, *slowly*, a good 15-20 times so that the new fluid is thoroughly dispersed throughout the fork's inner workings. Now, again, with the fork springs NOT in the tube, and the fork leg *fully* collapsed, add suspension fluid until the level is exactly 150mm from the top edge of the fork leg.

Once this is done, you reach in for the last time and pull out the damper rod to it's max extension, quickly slip the fork spring over it and "catch" the damper rod before it slowly settles back down into the tube (as you can no longer reach it if it settles to the bottom since the springs are now in the way).

Now slip in the spring seat washer, and finally the long spacer tube. Thread on the top cap and lock it down with that 14mm lock nut seen above. Now just raise (extend) the slider tube up high enough so that you can thread that top cap down into the slider tube.

Torque down the top cap to spec, re-install the forks, and you're done...

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Are you guys using the Pro Honda SS-8 10wt for fork oil or having success with heavier oils? Rich at Sonicsprings is telling me that since its a cartridge fork oils heavier than 10wt will flow too slowly and make damping too harsh. Experience with heavier fork oils?

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Are you guys using the Pro Honda SS-8 10wt for fork oil or having success with heavier oils? Rich at Sonicsprings is telling me that since its a cartridge fork oils heavier than 10wt will flow too slowly and make damping too harsh. Experience with heavier fork oils?

Most folks around here seem to either stick with Stock or go to lighter weight fork oil. I'm going to try 5WT next myself.

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Are you guys using the Pro Honda SS-8 10wt for fork oil or having success with heavier oils? Rich at Sonicsprings is telling me that since its a cartridge fork oils heavier than 10wt will flow too slowly and make damping too harsh. Experience with heavier fork oils?

Most folks around here seem to either stick with Stock or go to lighter weight fork oil. I'm going to try 5WT next myself.

I use 5wt with race-tech valves

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