Your Fox fork may feel like a million bucks, but if it's been awhile since you've performed any maintenance than there is a good chance that a little love will have it working even better. This job won't require rebuilding the damper, a repair that some will find intimidating, but only removing the lowers for cleaning and reassembling with new lube oil. How do you know when to get your hands oily?
Fox says to slide the lowers off once every 25 hours to inspect the seals and foam rings, but this is also the time to clean everything thoroughly and treat the fork to some new lube oil as well. Riders who spend a lot of time in nasty conditions or doing laps of the bike park will want to do it a little more frequently, but it never hurts to be an eager beaver when it comes to maintenance. What exactly does that oil in there do?
It's pretty simple actually, it acts as lube oil to keep your fork running smooth and active. The oil breaks down over time and loses its ability to lubricate the bushings, but it also gets contaminated from the elements. Small pieces of grime, water from hosing your bike down after a ride, and even tiny bits of rubber from your seals all pollute the oil, with the result being that nasty and thick gray sludge that you're about to pour out of your fork lowers. This sludge can not only have a negative effect on performance, making the fork feel sticky and unresponsive, but can also damage your stanchions in the long run. Think of that nasty oil as sand paper, because that's essentially what it is, with millions of invisible grits slowly working away to scour the finish right off of your stanchion tubes. Doing this repair will not only keep your fork running smooth, but it's also preventative maintenance that can save you money in the long run.Some pointers before you begin...
• There is a good chance that you're going to make a mess during this job, especially if it is your first go at it. Not only do I recommend wearing gloves and eye protection, but it also doesn't hurt to put down an old towel on the floor to soak up any spills. Be sure to properly dispose of your old oil as well, not by just pouring it down the drain!
• You'll be dealing with some small parts during this job, including the foot nuts and the very small detent ball and spring tucked up in the high-speed compression knob. Don't lose them! Having a small dish or container to put these bits in after removal can save you from spending a lot of time on your hands and knees scouring the floor.
• The video shows me removing the fork from the bike, this makes the job much easier, but isn't 100% compulsory.
• Both foot nuts, 10 mm on the spring side and 15 mm on the damper side, are aluminum. This makes them light, but more fragile than if they were steel. Use the correct size tool (not an adjustable wrench
) and take your time so as not to damage them during the repair.
• In the video you'll see that I'm using a rubber mallet to tap the foot studs lose from the lower leg assembly. I can't stress enough to never use a standard hammer for this.
• Once you have the lowers off, take a few minutes to inspect your stanchion tubes to be sure that they don't have any fatal scratches or dings in their finish.
• With your lowers off and the upper assembly in the upright position, stroke the fork's damper rod through its travel. It should take effort to stroke, but move freely and not feel notchy. If it feels as if it momentarily loses damping you'll need to service the cartridge, which we'll cover in a future Tech Tuesday.
• There is no point doing all this work and then not properly cleaning the inside of your lowers before putting them back on. You can use a rag and a long screw driver (just be sure not to scratch the bushings inside the leg
), or the long plastic handle of a kitchen utensil, to push the rag in and out of the fork. Spraying some non-corrosive cleaning solvent down the legs will help as well.
• When reassembling take note of the flat surface on the adjuster rod that the low and high-speed adjuster knob's setscrew tighten down onto. Be sure to line this up with each setscrew.
• If either of the foot studs spin when reinstalling the foot nuts, a bit of pressure on the fork can help a lot. Putting in the correct amount of lube oil is vital in order to have your fork working properly.
It's all about volume - too much oil and you won't be able to attain full travel, but you need enough in the lowers to lubricate the bushings. Our 180 mm travel 36 VAN RC2 requires 40ml of lube oil in both the damping and spring side, but it will vary depending on the fork model. Be sure to have a close look at the Fox oil volume chart
to determine the correct amount that your fork requires. Fox also recommends using their own special 10 wt. fork oil on models featuring gold Kashima equipped stanchion tubes. What's needed: 2 mm hex wrench
, 10 mm socket
, 15 mm socket, rubber mallet
, oil pan (an old Tupperware container works great
), measuring cup, 7 wt. suspension fluidWant to keep your Fox fork running smooth? Watch the video: