Spending a few minutes to remove and clean the lowers of your Fox fork
will not only keep it running smooth, but also act as preventative maintenance for down the road. Today's Tech Tuesday shows you how to drop those lowers and replace the all-important lube oil to keep your fork silky. Check out the tips and video inside to see how the job is done,
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:
While I didn't need to replace the seals on my fork, if you need to, follow the same dis-assembly procedure as stated above in order to remove the lowers. Once the lowers are off you can use an 18 mm open end wrench to pry the seal up and out of its bore, being careful not to score the inner surface of the leg. Don't worry about damaging the seals, you'll be replacing them anyway. Now remove the foam ring that was hidden under the seal. To install the new seals, first slide them up the stanchion tube, not into the fork lowers. This limits that chance of damaging the new seals during installation. After dipping the foam rings in your new oil, slide them up into position under the new seals. Now you can reinstall your lowers, sliding them up onto the stanchion tubes. Use your fingers to seat the new foam rings and seals into the seal bore. If the fit seems tight you can use a socket or another blunt tool on the seal's outer edge to push it in place. Never push on the dust wiper lip unless you want to buy another set of seals.
Need more info or some help? Check out the Fox Racing Shox website
to see their service guides.Have you done this job? Want to add a tip or hint of your own? Put it down below!
Past Tech Tuesdays
:Technical Tuesday #1 - How to change a tube. Technical Tuesday #2 - How to set up your SRAM rear derailleur Technical Tuesday #3 - How to remove and install pedals Technical Tuesday #4 - How To Bleed Your Avid Elixir Brakes Technical Tuesday #5 - How To Check And Adjust Your Headset Technical Tuesday #6 - How To Fix A Broken Chain Technical Tuesday #7 - Tubeless Conversion Technical Tuesday #8 - Chain Wear Technical Tuesday #9 - SRAM Shift Cable Replacement Technical Tuesday #10 - Removing And Installing a HeadsetTechnical Tuesday #11 - Chain Lube ExplainedTechnical Tuesday #12 - RockShox Totem and Lyric Mission Control Damper ModTechnical Tuesday #13 - Shimano XT Crank and Bottom Bracket Installation Technical Tuesday #14 - Straightening Your Derailleur HangerTechnical Tuesday #15 - Setting Up Your Front DerailleurTechnical Tuesday #16 - Setting Up Your CockpitTechnical Tuesday #17 - Suspension BasicsTechnical Tuesday #18 - Adjusting The Fox DHX 5.0Technical Tuesday #19 - Adjusting The RockShox BoXXer World CupTechnical Tuesday #20 - Servicing Your Fox Float ShockTechnical Tuesday #21 - Wheel Truing BasicsTechnical Tuesday #22 - Shimano Brake Pad ReplacementTechnical Tuesday #23 - Shimano Brake Bleed
to see their entire lineup of tools and lubes.