What goes into a Fox Triad service?
This is the first post in our new series showing you what’s inside a variety of shocks and what we do to service them and bring them back to life. We’re going to show you a few common faults that develop, resulting in partial or total failure of certain features like lockout and rebound damping and we’ll show you why these problems can only be fixed by a full professional service.
In this article we’re looking at a customer’s Fox Triad that came off a Specialized FSR full suspension frame. You’ll notice the odd looking fitment on the bottom of the shock which allows it to be attached to a cradle which forms part of the suspension linkage assembly, rather than the usual eyelet that you see at the top on this shock and on both ends of most shocks that you’ll probably be more familiar with.
This particular customer came to us complaining that the Triad lever and rebound adjuster knob wouldn’t turn and the shock felt pretty awful when riding. Also the shock wasn’t holding air for longer than an hour or so. On first inspection it wasn’t clear exactly what the issue was with the lever and rebound knob, but they wouldn’t turn at all so at the very least a full strip down and service was needed and possibly some new parts inside, depending on what we were going to find inside.
We stripped the shock down and removed all parts for a full chemical clean and a thorough inspection to try and locate the source of the issue. As you’ll see from the picture above, all of the damping fluid had escaped from the damper, meaning that the lockout wouldn’t have worked even if the adjusters would turn, so already that’s one thing that we could sort out straight away. The white disc you can see inside the damper body is the Internal Floating Piston (IFP) which should be set a lot lower than that. It’s at the height you can see due to the oil leaking out and the nitrogen pressure that is underneath it pushing it upwards. More on that later.
The photo above shows what we do for every shock that comes in for a service. We’ve stripped it down to the absolute ground so that we can inspect every part for damage and replace every single seal on the shock so that it is essentially a brand new shock that you get back.
These are all the seals and bushes that come out of a Triad. As you can see, that’s a lot of stuff that can wear out and cause you problems! Only a few of the seals there are user replaceable, the rest are deep inside the shock and need a specialist to access in order to avoid damaging the more delicate parts of the shock.
The tiny little light coloured seal that has blown is the cause of the loss of fluid. You can see the new one next to it for size. Not a very big seal at all so you can see why the service interval on some shocks is so low. If your shock loses damping or lockout then there is a chance that this might be to blame. This one had totally failed and at some point the fluid will have flooded out of this shock. Unfortunately for our customer they didn’t realise and the person that sold it to them didn’t bother to mention it.
We refill the shock with fresh damping fluid which will bring back that smooth, new feeling. A lot of people don’t realise that this is actually one of the most important parts of the service because the fluid gets degraded over time and will not perform as intended, so a change will make a big difference.
With all the seals replaced throughout the shock we join the damper back to the damper body, bleeding any air out to ensure a proper damping performance throughout the shock’s stroke.
The final step before popping the aircan back on the shock is to refill the IFP chamber with nitrogen at 500psi via the needle that you see above. The IFP allows for the displacement of the piston in the oil by being able to move as the shock compresses and it also stops the oil cavitating or bubbling up, to keep the shock performing throughout the stroke. The reason that we use nitrogen, apart from it being the gas that Fox Racing Shox recommend, is because it’s essentially inert and won’t react with the rubber seals like oxygen will. This prolongs your seal life and therefore increases the time between services. This part of the service is pretty dangerous if not done correctly. Getting nitrogen at 500psi in your hand is going to sting.
And here it is, all shiny and clean, ready to shred. We always test the damper on the shock to ensure that it is performing as we expect it to. This shock now has its 3 stage damping back, including lockout. The lever and rebound dial work as they are supposed to and the shock is smooth in operation and holding air. Job done.