IFP Depth on Pushed DHX 5.0

[LowLow]

PUSH serviced my DHX 5.0 shock a few years ago, and I recently decided to open it up and do an oil change myself. When I took the shock apart, I noticed that the IFP was set to 15/16" (.9375"). The stroke on my shock is 2.25", so the IFP depth is supposed to be 1.3" according to what I've found online. I've ridden it after the oil change and it seems fine, better in some ways, but also a bit more dead.

Now I'm wondering if I should reset the IFP to 1.3", or if PUSH set it to 15/16" inches based on the tuning they did. Any ideas or suggestions?

[tacubaya]

Ask PUSH

[LowLow]

Ask PUSH

Yeah, I'm gonna do that, but I was just curious if anyone here has any insight.

[Matty F]

While I don't know if Push would alter the IFP depth, I would bet on the fact that you found the IFP in the improper position if it's been a few years since you last rebuilt the thing. Especially if it's the kind of riding that merits a DH shock. Air creeps past the IFP in to the oil chamber and thus shifts the IFP position over time.

[PMK]

While I don't know if Push would alter the IFP depth, I would bet on the fact that you found the IFP in the improper position if it's been a few years since you last rebuilt the thing. Especially if it's the kind of riding that merits a DH shock. Air creeps past the IFP in to the oil chamber and thus shifts the IFP position over time.

You might consider that air is drawn into the shock body during compression movements. Not gulps of air, but rather very small amounts that add up over time. This is caused from the finish on the shaft, and the cavitation on the piston backside helping to pull the air inside.

The IFP moves very little, and the pressure differential from rezzy chamber to oil side is very low.

PK

[LowLow]

Thanks for the replies. I actually called Push and they said that they don't actively move the IFP depth, but the way they work on the suspension, the IFP depth may or may not move. I didn't really understand why or how, but I'm thinking I'll move the IFP back to 1.3" just to see how it feels. This would make it more linear, which I think would be nice because the suspension feels a bit soft during the initial part of the stroke in a way that I haven't been to fix with a firmer spring.

The other thing is that I only had 75psi in the boost valve, which is the minimum for my shock (from 2007). The minimum became 125psi from 2008 going forward, and I read some where that Fox later on recommended 125psi for the earlier versions too, so maybe that caused the IFP to move over time. Before moving the IFP, I'm going to run it at 150psi for a while to see how it feels.