WP Inner fork tube and rebound valve

How to get the inner tube out is covered in the post I did about replacing the fork seals.

Have later found an easier way to get to rebound tap, that wont require breaking inner leg apart

So had just gotten the forks back together but there was some issues with the rebound adjuster so had to tear them apart, had changed the seals and cleaned things up as best and reassembled and added fresh oil, did not flush any fresh oil around in the forks and here is was the new oil looked like:

Some junk in the oil

So in the future I will for sure flush the forks with some fresh oil during an oil change!

And I know you are supposed to use special clamps to hold the parts to avoid damage and if anyone reading this have a good source for the specialist tools for this please let me know, add a comment.

But an 8.5mm drill in a wooden block and a bench wise worked also, no damage could be seen or felt.

8.5mm drill to hold tube

Once that lower tube is removed the rebound valve assembly is exposed two pieces of wood clamped together and drilled in the middle to form grooves did not provide grip enough so some rubber was added:

Clamped in place

Notice the hammer, that is a must to get enough of a shock effect to loosen the valve assembly:

Clamped in place

This one was a lot worse then the other here there even seems to be some sand and gunk not good, have the speed bleeders let debris in? The other one mainly showed corrosion on the distance tube and that was binding, here the distance tube looks fine but the spring is quite rusty and the needle valve won´t come out, some WD-40 was not enough actually had to hammer it in a little to be able to start moving it:

Rebound valve loosened

Once out:

Rebound needle valve out

Had a new O-ring for the needle valve:

Removing O-ring

Hard to get good pictures but there is corrosion inside:

Rebound valve corrosion

Soaking in WD-40, NOTE this had a seal around it that was never showed in any photo and it comes off real easy, don´t loose it:


Still a little left a little piece of nylon scrubber to try to get in there:

Rebound valve

Inside of the tube the rebound valve bolts to is also quite corroded, got the same WD-40 soak and some scrubbing, hard to get into here:

Had this been my primary set of forks I would probably have changed some parts but this is right now a spare set so this will have to be enough!

Quite some corrosion

Back together just reverse the disassembly, rebound valve assembly calls for some Loctite I just used 243 that I had at home.

Have written up a few tips and trix that might help out if working on these forks.

2 comments to WP Inner fork tube and rebound valve

  • Simon MacArthur

    Just found you on Advrider. Nice looking site man. I’ll be checking in often.
    I just did a stretch on my forks so I liked your photos – been there done that – and it’s not easy getting a proper grip and torquing things down to spec but we have to do these things don’t we?

    On to the shock next but I don’t have the necessary gear to recharge the nitrogen so I think I’m sending it out to a guy in Washington State.

    • Johan

      Would be nice to have the special tools for the job but if not having them it can be good finding ways to work around it.

      Regarding stretch I ended up buying a 320mm Pyndon suspension, I see plenty of low speed tip overs in my future!

      There will be a writeup about that later on.

      Have tried tackeling a rear shock on a smaller dirt bike once before but needed help with the nitrogen filling so have for now just had a suspension guy change the oil and refill.

      Would eventually like to go over a rear shock at some points …have ended up with 3 sets of forks and rear shock so there will not be a problem if a shock ends up in pieces for a longer period of time wont cause any downtime in riding.

      Actually trying to sell 1 set of forks and rear shock but guess shipping to the US would be quite expensive from Sweden.

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