Hi All,

Running a fox RP23 on a Marin Attack Trail Rage, with 140mm travel. My rear shock is charged to 130PSI (I'm a very svelte 13,5 stone!) yet of late, my travel seems to have disappeared! It used to be fine, but after last nites ride, I was losing half my travel to sag, and the back end was really wallowing. I was convinced that the shock had lost pressure, but upon checking was fine! Anyone else experienced this? I don't want to keep upping the pressure in a potentially damaged shock!

Thanks all

Slight air leakage into the negative side?

I'd give TFT a call – they should be able to give you an indication of whether it's a home fix or a send off for repair (and I'd avoid Mojo unless it's still under warranty)

As Clubber says it sounds like an air leak.
Mine did this a few times and i took it apart myself following the instructions on the Fox website for repairing a stuck down shock.
I eventually binned it and put a coil on!

Its just stuck down, yes the air has crossed a seal into an area it shouldnt be, they sometimes do it, mine did it about a year ago, though a different fox shock, a septune, my mates triad did it too, you need to remove it from the bike and let the air out of it, then unscrew the air chamber it will make a horrific bang and scare the shit out of you, then just clean it all out inside the air chamber and re assemble using for fork or shock oil liberally inside it. A vice helps, but I did one trailside once.

I think you can get a more grease like lube to put in it, but I just use fork or shock oil now and do it fairly regularly as it helps the seals and shock shaft last. I didnt have to do anything else to mine and its never had to be sent off.

Thanks Tinsy.

Is it stuck down? The shock still works, albeit like its got a really low PSI. I thought stuck down meant just that?

It doesn't sound stuck down.
Let all the air out, squidge it a few times and let air out again. Pump it up again. If pressure is correct (I'm 14' and run 190 on a kona), could be a damping issue? Call TFT or Mojo.

Yeah axact same symptoms, eneded up running a ferrocious pressure just to get the ride height back, pop the air can off and it will be fine, but it does make quite a bang. Its worth doing an air can service regularly anyhow as it really makes a difference to how long the shock last.

it's stuck down.

get a LBS to remove the can (suspect the neg chamber will be charged with pos pressure air so don't remove it yourself as the air can will litterally shoot off the shock when you undo it)

all it needs is a little grease on the seal and bobs your uncle… (unless the seal is shot then you need a new seal too)

When not loading the shock, does it return to full length – if so it's not stuck down. If it doesn't return, it is.

It is stuck down, the air has gone to the wrong part of the shock and the pressure is actually holding the shock down (dunno how it just does), you can keep adding air to the chamber to counteract it, but you need to release the trapped wind!!

Whatever, its a free fix and well worth a try before you send it off.

Certainly sounds stuck down
Relativity easy fix, see here for details – You'll need to be logged in to see the pics

http://forums.mtbr.com/showthread.php?t=401486

'Stuck down' in just the symptom of when it gets really bad – yours is just partly stuck down probably because some air has leaked into the -ve chamber. As more leaks, it'll eventually become properly stuck down.

YUP.

Cheers chaps!

Might try for a warranty fix from Mojo, as the shock is 14 months old, and warranty is specced at 2 years in the EU on their website!

NS

If you have not done the air can service for 14 months and they open her up and its dry as a bone, they will probably charge you. The Fox site says its a thing to do every 8 hours riding. They will even if warranted probably charge for parts as they wont put it back together without new seals.

If your not comfy with doing the air can service, then thats your only option, maybe worth ringing them to see how you stand.

As above…^^ tinsy is bang on.

Its really easy to do
click this link and select air sleeve maintenance

TF Tuned sell a service kit for about £12

Mine stuck down after 18mths Mojo fixed it no questions asked, so a big thumbs up from me. When it happened again, out of warrenty I did it myself,just get the seal kit for £12 and your away. I took a vid of me unscrewing the air can, It does make a bit of a bang !!!

You really did video that! Jeez 1:51 of my life never to return

Hi Guys,

Removed air can to see if the shock was stuck down. Not even a "pop"! Actually unscrewed it by hand on the bike no probs at all, and all still seems nice n lubed in the internals! I've inflated the shock to 180 PSI now to see how I get on. One thing I've noticed, the travel adjuster turns continually (I can go from 3-1 and vice versa) Is this normal?

Ta

NS

travel adjuster? You mean the propedal setting?

maybe a silly question but are you sure the rebound damping isn't just wound all the way on? this will make the shock slow to come back out.

Chaps,

My shock has 3 settings – hard, medium, soft, along with pro-pedal on & pro-pedal off, and the rebound is set somewhere in the middle to be honest

NS

Northshaun, how much do you weigh? edit 13.5 stone.. I am 12st + depending on the weather and run about that, however remeber the gauge on the pump could be well out as they are crap, best to set the sag right to get the shock right.

I Just re read you OP and didnt twig before sorry, 130psi is too low for your weight, bikes vary with leverage ratios etc, but 130 was just too low!!

told you so, told you so, told you so………. 😛

Tinsy,

Am pumping up to 190psi, as you seem to lose 10psi when disconnecting. Bike seems good now, but I'll trial it over the next few weeks. It just seemed odd that all of a sudden the back end seemed wallowey! Mebbe I should put it down to 2 weeks abroad, eating & drinking too much & hiring a really cheap & nasty hardtail?