How To: Installing Fox Float X2 Volume Spacers

In this MTB How To, we are going to install some volume spacers in to a Fox Float X2 rear shock. First we are going to go over what volume spacers are and why they can be important to getting the most performance out of your shock possible. Let's begin!

What Are Air Volume Spacers?

Air volume spacers allow you to tune the spring characteristics of your rear air shock. Adding a volume spacer to your rear shock reduces the volume of the positive air chamber. And of course removing a volume spacer increases the volume of the positive air chamber. With the maximum amount of volume spacers (ie. least air volume) the shock requires more force to compress at bottom. This means the shock is more progressive and that it ramps up at the bottom of the stroke. Check out the graphic below!

• So say you want to add a volume spacer to increase the bottom out resistance on your shock. You might end up running less air pressure in the shock to achieve the same sag as before to get the best small bump compliance from your suspension. Learn how to set suspension sag by checking out our MTB How To.

If you need some more Float X2 volume spacers for your shock, we have them for you!

How Many Volume Spacers Should I Have In My Rear Shock?

There is no set answer to how many volume spacers you should use in your rear shock. Each bike has a different suspension leverage curve with different suspension characteristics. So for each bike, the number of volume spacers to get the most performance out of your Float X2 may change a little. 

• If you have set your sag correctly and are using full travel (bottoming out) too easily, then you could install another volume spacer to increase bottom out resistance. 

• If you have set your sag correctly and are not using full travel, then you could remove a volume spacer to decrease bottom out resistance.

It is very important not to overfill the shock with air volume spacers. For each stroke length, Fox has a maximum amount of volume spacers that can be used. From a performance standpoint, you shouldn't have any reason to overfill the shock with air volume spacers.

New For 2017

For 2017, Fox has introduced a new volume spacer that can be installed while leaving the shock mounted to the bike. In 2016, the volume spacers were a one piece black rubber band. The new volume spacers are a two piece design and clip together inside the air can. This just takes one step out of the process from before. 

What Tools Do We Need?

• To get the job done, we are going to use a Fox digital shock pump, a 1.5mm allen key, and some volume spacers.

1. Release All The Air From The Shock

Now before you release all the air from your rear shock, make sure you know what psi you ride with currently. If you don't know, it's as simple as attaching the shock pump on the shock and checking the pressure. Keep in mind after changing the amount of volume spacers in the rear shock, the air pressure needed in the shock to achieve the right amount of sag may change. 

• Release the air pressure in the shock using your shock pump. Then use a small allen key to make sure all of the air has been released from the air can.

2. Remove Air Can Set Screw

All of the 2017 or newer Fox Float X2 shocks should have a small set screw as a safety to keep the can from twisting while riding. If your shock doesn't have this set screw, don't worry, just skip this step!

• Use a 1.5mm all key to remove the small set screw.

3. Twist and Slide Air Can Off

• Get a nice firm grip on the air can and twist it less than a quarter of a turn towards the oil reservoir. Doing so aligns a small tab that allows the air can to slide off.

• Slide the air can down the shock away from the oil reservoir.

4. Install Volume Spacer

• The process of installing or removing a volume spacer is very easy. The two orange spacers simply snap together around the shock body. If you are trying to remove one spacer for a more linear feel, do so now. And vice versa, if you want to add a volume spacer, now is the time. 

• Do not overfill the shock from the maximum amount of recommended volume spacers. Fox has information on the maximum amount of volume spacers for each shock length. 

5. Reinstall Air Can

• Now that you have the right number of volume spacers in the shock, slide the air can back up on to the shock. Align the tab on the air can, make sure it is slid all the way up on the shock body, and twist the air can less than an quarter of a turn away from the oil reservoir. 

6. Install Air Can Set Screw

• Install the set screw at the bottom of the air can using a 1.5mm allen key. 

7. Pump Up the Shock 

• Attach your shock pump, and pump up the shock to the same pressure as before. Make sure to equalize the negative chamber of the air shock while the shock pump is attached. Compress the shock through just the first part of the stroke to get the positive and negative chambers to equalize. Here I pumped the shock up to 135psi, equalized the positive and negative air chambers, and then continued to add pressure. Repeat the process to get the desired psi. 

• To learn how to set the correct sag on your mountain bike suspension, read our MTB How To!

• To always get an accurate reading, check out the various digital shock pumps available!