Did my Fox RP23 always top out?

bluechair84

I think it's an RP23 - the previous owner push tuned it and it is emblazened up as such.
Anyway, I have suddenly noticed that at full extension it clunks out... on a scale of 1-10... how mad am I? Did it always do that? If not then I think it had best go off the to shock fairies...

cavegiant

Could have cavitated.
compress and check rebound.
if has damping for the first bit, then shoot out, cavitated.

Thankfully an easy fix.
Send it to TF or Mojo, either way PAY FOR THE CUSTOM TUNE. It is only a few quid more than the service, but immensely improves the shock.

It usually is a warranty fix, so you might try to blag it.

bluechair84

what is cavitated?
The rebound and damping seemed fine - it's certianly not pogo sticking. But I can't remember if it always topped out. Are the Foxs fitted with something to supress top out?

cavegiant

cavitation is a leak in the damper (making a cavity)

The top out is controlled by a fluid circuit.
Fluid being sucked through a hole limits rebound speed, unfortunately if all the fluid is not there then air will be sucked through after the fluid.
This means normal rebound followed by a harsh top out.
As it gets worse it will snap back further and further in the rebound.

The red dial on the front of RP23 is rebound damp. put 100% rebound on, fully compress and let it slide back out. It should take a couple of seconds (mine takes about 10, apart from when it cavitated, then it took 1 s).

One other check is opening the can, you might see damper fluid in the air chamber.

Might be something else, but this is a common fail when a shock is not serviced enough.

Locotuning

It sounds like cavitation, nitrogen in the oil chamber due to the seal on the IFP 'going' full service will sort this. Is it making a squelching noise too?