FOX has an excellent description of how these technologies interact.
Air Volume Tuning: For this particular shock size, 4 air volume reducers are installed at the factory and 4 included in the box. Volume spacer installation requires removing the shock from the bike, but nothing beyond that.
The procedure overview is:
- Remove the shock from the bike (8mm, 6mm and 5mm hex keys for the Enduro)
- Carefully de-pressurize the shock
- Rotate the air can slightly (there’s a keyed tab)
- Slide the air can off
- Add or remove the spacers as desired
- Reassemble and revise damper settings as desired (e.g. less volume lends itself to reduced high speed damping needs, as the spring’s rate will increase faster while deeper in the travel)
Official instructions from FOX can be found at www.ridefox.com.
Air can volume is fairly easy to adjust trail-side or in the parking lot, just taking a few minutes, but be very careful to avoid getting any dirt into the system!!!
FOX lists 125 hours as the service interval, which is on-par to slightly better than the competition.
In response to many riders’ search for a DH oriented damping solution for their current generation Specialized Enduros, FOX has created a Float X2 that fits. This is a similar shock to what was seen on Gwin’s Enduro last season, however, does not require frame modifications to fit! These frames are too expensive to void the warranty for most riders, so an approved solution is definitely appreciated.
When this was written, the Enduro’s shock size was missing from the FOX web site, but it is available: 8.5×2.25.
Riding the X2
The first step is setting sag. This will let the rider know how much air pressure achieves the spring force required to support their weight. Once this is known, FOX provides suggested damper settings based on that pressure, which I used as the starting point. After that, it was time to ride and dial in the tune for the bike’s specific geometry and rider preferences.
During the ride, even after adding multiple clicks of HSC damping, bottom-out was happening often and abruptly. I added two additional volume spacers to ramp up the spring rate when deeper in the travel. The combination of 6 total spacers and a couple additional clicks of HSC and HSR damping provided a well behaved ride for sharp hits and jumps.
Low speed settings were next on the list. Starting with the baseline, I added a few clicks of LSC to firm things up (to reduce travel for both pumping and pedaling) and found pedal bob to be reasonable. My rides tend to be pedal-commutes to the fun stuff, so climbing performance is not a priority and the climbs are definitely not technical ascents. As with HSR, LSR should be as open as possible, allowing the shock to extend after a compression, without being too lively. These settings are highly dependent on both the bike and rider, so spend some time playing with them.
If the shock was being used for DH only (shuttles and lift-served), I’d run less LSC. For improved pedaling performance (e.g. longer climbs), the LSC valve could be closed. I rarely did this, as that adjustment requires a tool and remembering to reopen it before descending. Photos have circulated online showing an X2 equipped with climb switch on FOX riders’ bikes, so keep your eyes peeled.
After the initial tuning, adjustments have been minimal and mostly exploratory. Terrain has mostly consisted of steeper offerings in the Santa Cruz area (flowy high speed trails with moderate roots and rocks), plus some additional jump spots to collect air miles.
The end result of testing this shock: it’s not going anywhere. The Float X2 is staying on my Enduro.
The X2 is perfectly tailored for the aggressive all mountain and DH rider. Yes, there is some pedal bob, which I can live with because of the downhill performance. A climb switch would be a welcome addition. Long term durability is the only unknown, so we’ll see how it rides over the next year. My hope is performance will gradually decline as the seals age, rather than catastrophic failure (which I’ve experienced with other shocks on this bike, grumble). For my personal riding and bike, the X2’s closest competition was the Öhlins Coil, yet the X2 does not have a weight penalty.