Review by Johan Hjord // Photos by Nils Hjord, Johan Hjord, and Brandon Turman
We first spotted an interesting new rear shock design from FOX’s Racing Application Development (”RAD”) program on Greg Minnaar’s World Champs bike in 2013. Fast forward to spring of 2015, and the DHX2 and Float X2 shocks were publically introduced, taking direct aim at the gravity crowd. Based on a twin-tube damper design, a first for the fox tail, the new shocks are FOX’s most adjustable offering to date. Together with the Float 36 RC2 fork we reviewed earlier this year, we laid our hands on the airsprung Float X2 and set off to find out how it performs on a hard-hitting trail bike.
2016 FOX Float X2 Highlights
- Made for All-Mountain/Enduro/Freeride/DH use
- Kashima coated body
- External adjustments: low-speed compression, high-speed compression, low-speed rebound, high-speed rebound, air spring pressure.
- Extra-Volume (EVOL) air sleeve
- Tunable air spring via volume spacers
- Travel options: 7.875 x 2.00, 7.875 x 2.25, 8.50 x 2.50, 8.75 x 2.75, 9.50 x 3.00, 10.50 x 3.50
- Weight: 515 grams (8.50x2.50)
- MSRP: $595 USD
You know how some parts show up all understated, almost timid? That’s most definitely not the case with FOX’s new Float X2 shock. With an extra-fat air can, 2 big adjusters and a matt black finish, the X2 looks nothing if not purposeful.
Of course, the X2 was essentially made for gravity applications, so the imposing looks come as no surprise. Our 8.50x2.50 tipped the scales at 515 grams, a weight penalty of 115 grams compared to the RockShox Monarch Plus it would be replacing.
The great novelty of the Float X2 (and its coil-sprung brother the DHX2) is the twin-tube damper design, a concept similar to that found on Cane Creek and Ohlins shocks. Twin tube refers to the construction of the main body of the shock, which houses one tube inside another (you’d be forgiven for thinking it has something to do with the two tubes housing the compression and rebound adjusters, but this is not where the name of the design comes from).
The purpose of the twin tube design is to provide a “recirculating” oil path, as opposed to a single-tube design where displaced oil has to travel back along the same path when the shock rebounds. This in turn is said to improve the reactivity of the shock and also helps avoid cavitation (which is when a quantity of oil vaporizes under intense pressure changes, which can in turn change the damping characteristics of the shock). A traditional "needle and port" valve provides low speed tuning, while the high-speed rebound and compression damping is independently adjusted via the "Rod Valve System" (RVS). RVS is an adjustable, spring-loaded shim stack - increasing the spring preload means you need a bigger impact to open the the circuit in question. There is also a final-stage blow-off valve on the main oil piston for those extra big hits. The following video provides a good illustration of the concept in action:
Much like the Float 36 RC2 fork we reviewed earlier this year, the X2 shows off with impeccable build quality and finish. Testing out the adjusters (3/6-mm allens required) the clicks were positive and easy to feel/hear. On the subject of the adjusters, there are more knobs to twist here than you might know what to do with at first. Fully adjustable (lots of clicks!) high and low speed compression AND rebound, adjustable air spring pressure as well as air spring progressivity thanks to a system of air can tokens. The X2 is not meant to be a plug-and-play type of product, nor is it aimed specifically at trail riders, as evidenced by the lack of any kind of external platform or lock-out switch.
A final word on the Extra Volume (EVOL) aircan. Although the X2 is a brand new shock, the EVOL aircan concept is a recent FOX development that can be found on the company’s more trail oriented shocks as well. The idea is that by increasing total air volume as well as the size of the negative air spring, the same shock can benefit from better small-bump action. This and more is what we were now eager to put to the test on the trail.
On The Trail
The Float X2 is fully adjustable externally, which means that the only thing you have to worry about when buying it for your bike is whether or not they make the right size, and getting the right hardware. The “base tune” of the shock is basically always the same, it’s up to the user to adapt the shock using the external adjustments to suit the characteristics of each particular frame. To be completely accurate here, the blow-off valve of the main piston features two shim stacks that are in fact reversible to change tune, allowing you to flip the shim stack if you need less blowoff. FOX told us pretty much everyone runs the stock configuration though. To get us going, we mounted up the shock and adjusted everything as per FOX’s recommended settings. We started out with 4 volume spacers in the aircan, which left us running 190 psi for 30% sag, with a 200-lbs rider.
Hitting the trail, the first thing that stood out was the smooth and supple action of the X2. Even compared to the “Low” tune Monarch Plus we previously had on this bike, the X2 had more of a “DH” feel to it. We won’t go as far as to compare it to the action of a coil spring, but it does get pretty close. The YT Capra we used for this test has a very progressive leverage ratio curve, which lends itself well to riding with a lot of sag. We quickly found that we could drop the initial air pressure and not experience any bottom out issues, and at around 180 psi the bike really came alive in the rough stuff.
Playing around with the volume spacers in the air can (which is a simple thing to do), we found that we could significantly affect the progressivity of the shock. With a total of 7 spacers (that number goes up to 12 if you run the 3.50 stroke version), there’s a nice and wide range available. We eventually settled on 3 for the Capra.
So what about all those adjustments then? Each adjuster has a wide tuning range (24 clicks per adjuster) going from pogostick open to fairly harsh/slow – but even if you close all 4, the shock does not lock out. The transition between low speed and high speed damping action is completely seamless on both sides, and there are also no “hot spot” clicks within the tuning range (some shocks have one or two clicks that have a disproportionately large effect on the damping action – not so with the X2). Want to run less pressure but not bottom out? Dial up the high speed compression. Want to glue the rear wheel to the ground over uneven ground? Dial up the high speed rebound. Need more support in the turns? Add a few clicks of low speed compression and away you go. The action of the X2 remains very smooth throughout the whole tuning range.
As for our settings, we ended up adding a couple of clicks of low speed compression as well as a couple of clicks of both rebound adjusters compared to the recommended settings.
The shock lacks any kind of platform or lock-out switch, and we noticed a bit more pedal bob with the X2 compared to the Monarch Plus it replaced. You can choose to add a bit of low speed compression and rebound to reduce the bobbing, but as we previously mentioned, even if you close every available adjuster the shock does still not lock out completely. We have seen shots of a “climb switch” prototype in development, and it would not be a stretch to imagine it appearing as an option on the X2 fairly soon. Judging by what we see below, we’d wager it’s a low-speed compression lockout that remains independent of the other compression settings. With any bit of luck, it will be available to retrofit the current X2 as well.
In the absence of the climb switch, we’d say we gave up a few percentage points of climbing efficiency with the X2, but it’s not more than that. On this particular bike, the advantages more than outweigh the inconvenience of slightly more weight and a little bit more pedal bob. If your frame design relies heavily on the shock’s platform setting to climb well, your best FOX bet in the meantime would be the new Float X.
A final word on damping consistency. The twin tube design was among other things specifically developed to combat cavitation and heat build-up. We have not noticed any strange behavior from the X2 even during long and intense descents. Pounding rocks for 10 minutes left us with the same damping performance at the bottom of the run as when we started it. The only caveat we’d add here is that we tested during the cooler winter months – we’ll update this review when temperatures start to climb if we notice an effect on damping performance.
Things That Could Be Improved
This is going to be a very short list. Within the given design parameters, i.e. build a fully adjustable, DH-worthy airshock, we’d have a hard time figuring out what FOX could do better here. If you are worried about the extra weight and/or need a pedaling platform switch, you’re probably not looking at the X2 in the first place. We’d welcome the addition of a climb switch to make the shock more versatile and more efficient in racing applications (cough enduro cough), but by the looks of things, FOX are ahead of us there and will have a climb switch option available soon.
Long Term Durability
We’ve been doing our best to torture the X2 for about 2.5 months now, with nothing to show for it except for the good times we had along the way. Mud, dust, and rocks have left no visible signs on the shock body itself, and the X2 performs as well today as it did when we got it. FOX recommends a full shock service (by a FOX-certified technician) after 125 hours, which is not particularly onerous for most casual riders. Note that a basic air spring service is not officially required before the 125 hours are up. We will test this assumption and more, and we’ll come back and update this review if we uncover any particular long-term issues down the line.
What’s The Bottom Line?
Smooth, coil-like performance in a highly adjustable, airsprung shock – the FOX Float X2 provides the perfect solution for those looking to drop weight from their DH bikes or add another dimension of descending prowess to their trail bikes. The tuning range is wide, but remains largely usable even at both ends of the spectrum. Finding a good base setting is well within reach of the intermediate rider willing to put in a bit of time with a pair of allen keys, while expert racers will be able to eke out every last drop of performance thanks to the multitude of tuning options available.
More information at www.ridefox.com.
About The Reviewer
Johan Hjord loves bikes, which strangely doesn’t make him any better at riding them. After many years spent practicing falling off cliffs with his snowboard, he took up mountain biking in 2005. Ever since, he’s mostly been riding bikes with too much suspension travel to cover up his many flaws as a rider. His 200-pound body weight coupled with unique skill for poor line choice and clumsy landings make him an expert on durability - if parts survive Johan, they’re pretty much okay for anybody. Johan rides flat pedals with a riding style that he describes as "none" (when in actuality he rips!). Having found most trail features to be not to his liking, Johan uses much of his spare time building his own. Johan’s other accomplishments include surviving this far and helping keep the Vital Media Machine’s stoke dial firmly on 11.