The 2010 BoostValve-equipped ones have an internal nitrogen chamber, located at the bottom of the shock's shaft. However, the pressure is only known by Fox and the bike manufacturer, and its acces is sealed, since Fox does not feel it could be user-serviceable. The aftermarket ones should be available starting at a nitrogen pressure of 125psi, with 25psi increments from what I have read in some magazines.Yeah, Fox is pretty tight lipped about that stuff.
Was hoping someone here would know.
Maybe I'll try the Push guys?
Trust me, this info not even known to bike manufacturer in many cases. We have asked.The 2010 BoostValve-equipped ones have an internal nitrogen chamber, located at the bottom of the shock's shaft. However, the pressure is only known by Fox and the bike manufacturer, and its acces is sealed, since Fox does not feel it could be user-serviceable. The aftermarket ones should be available starting at a nitrogen pressure of 125psi, with 25psi increments from what I have read in some magazines.
Yeah, pretty much what I figured, except that when you get oil hot a bunch of times it can break down and get worse. Does seem like it heats up quicker now.Since heat/fading/oil thinning is the problem I don't see any solution. Small oil volume surrounded by an insulating air can is the issue. I feel this on my Mojo but it's the price you pay to descend hard on a lightweight shock. I think Push's staged rebound cures this some but it will still get faster when the shock heats up. Rockshox's thermally sensitive, expanding rebound needle is a novel solution and my friend who's testing it says it works great on long DH runs. I think that you'd still feel the compression damping fade and the air spring get stiffer from heat. Basically, if you want a shock that is consistent on long descents you need a coilover with piggyback (lots of oil to absorb heat & lots of surface area to lose it).
Any changes you make to the pressure will only affect the progressiveness/overall spring rate. Changes to oil weight will affect the feel of the shock at all temperatures and the damping will still get lighter as it heats up. Are there any brands of shock oil that are known to be significantly more thermally stable? I'd think not, or wouldn't Fox use it?
Mine says right on it. 200 psi.The 2010 BoostValve-equipped ones have an internal nitrogen chamber, located at the bottom of the shock's shaft. However, the pressure is only known by Fox and the bike manufacturer, and its acces is sealed, since Fox does not feel it could be user-serviceable. The aftermarket ones should be available starting at a nitrogen pressure of 125psi, with 25psi increments from what I have read in some magazines.
This was previously theorized, but no dice. I mean,the oil sprays out quite a bit when the actual valve is compressed via my finger or pump. Why else would Fox stealthy send me a new shock? Must have been a major malfunction. As of last night, I'm also noticing I have an oil leak around the juncture of the schaeder valve down by the body of the shock. Hmmm.The only thing on the other side of that schrader valve is the air volume inside the can. Maybe that's just some lubricating oil coming out because the valve is at the bottom? Fox didn't used to put oil in the can but a lot of use do to keep it slippery so maybe they've followed suit?
That's what I'm thinking. Taking off the air can will solve the mystery.It is entirely possible that the oil you saw was from a blown damper which is encased within the air sleeve.
The color of the oil is (I believe) red. I literally have to hang my shock pump (not that it matters, but it is a "Fox brand" pump) to drain after checking air. My temporary solution? Don't put any air in it! Seems to be holding thus far, I always have at least 1/4 inch left on the shaft/not bottoming out.There is oil in the air can. It's that thick Fox Fluid and it is blue. I have a bottle of it and use it when I do air sleeve maintenance. I get seepage past the main seals which turns up on the shaft but that's not a problem as I never seem to loose any air. I can't say that I have noticed any spitting out the shrader valve because I always use a shock pump so there is nowhere for any oil to go other than into the pump.
But it is entirely possible that the oil you saw was from a blown damper which is encased within the air sleeve. What colour was the oil?
Any news/info about making the internal service ?I found a russian website (I can not find it again, sorry) that has the blue print of the RP23 specifing torque, presion, IFP and oil volumes.
I did repair my own RP23 succefully using this website instructions but it is a very long story indieed, I am in a testing period rigth now but untill i solve some problems I just put presurized air instead nitro.
Let see if I can find the url again.