A little over a year ago the first images of FOX's Float X2 shock began to pop up, and by the time the World Cup downhill season began, a number of athletes were aboard the new air sprung shock, most notably Aaron Gwin, who ran the float X2 on his way to clinching the World Cup DH overall title. Gwin's already shown that he doesn't need a chain or tire to put down an outstanding race run, so trying to judge a component's performance based on his results doesn't really hold water. For that reason, we got our hands on a production model of the Float X2 as soon as we could and have been giving it a thorough shakedown over the course of the last three months.
FOX Float X2 Details
• Intended use: all-mountain / downhill • EVOL air sleeve • Adjustments: high- and low-speed compression, high- and low-speed rebound • Weight: 506 grams (8.5 x 2.5) • MSRP: $595 USD • www.ridefox.com / @foxracingshox
Billed as FOX's “highest performing air shock,” and aimed at gravity-oriented riders, the Float X2 has externally adjustable low and high-speed compression damping, as well as low and high-speed rebound adjustment. The amount of ramp up at the end of the shock's stroke is also adjustable by sliding off the outer air sleeve and adding or removing volume spacers as needed. There are six sizes available, starting with a 7.875” x 2” option and going all the way up to 10.5 x 3.5”. Our 8.5” x 2.5” shock weighed in at 506 grams. MSRP: $595 USD.
A look inside a coil X2, which uses the same internal design as a Float. Photo: Mike Levy
The Float X2 uses a twin tube design, which is pretty much what is sounds like – a smaller tube is situated inside a larger tube, with bleed holes strategically situated at the bottom of the smaller tube to allow oil to circulate as the shock goes through its travel. Credit goes to Cane Creek and Öhlins for being the first companies to bring this design to the mountain bike world back in 2005, although it had existed on cars and motorcycles for many years prior.
How does it work?
When the shock is compressed, oil flows from the main tube, through the compression circuit, and then through the outer tube's bleed holes into the area behind the main piston. On the rebound stroke the process is reversed: the fluid exits the bleed holes, travels back through the outer tube, but this time it travels through the rebound circuit. The use of one-way check valves ensures that the oil reaches the correct destination during the compression and rebound portion of the shock's stroke.
Low-speed rebound / low-speed compression adjustment: When the 3mm hex screw is turned to adjust either the low-speed compression or low-speed rebound (there are 24 clicks for each), it moves a needle valve that regulates the flow of oil. The smaller the port gets, the harder it is for oil to pass through – imagine a crowd of people trying to push through a partially opened sliding door – which means that the shock will either be harder to compress or rebound slower, depending on what circuit is being adjusted.
Now open that sliding door all the way and the crowd moves easily and quickly through it, which correlates with reduced compression damping and quicker rebound speed, again depending on which circuit is being adjusted.
A 3 and a 6mm hex key are necessary to dive into the shock's adjustments, with compression adjusted on the blue side and rebound on the red.
High-speed rebound / high-speed compression adjustment: High-speed rebound and compression are independently adjusted by FOX's Rod Valve System (RVS). Turning the 6mm hex screw compresses a spring that increases the preload on the rod valve's shim stack, causing a greater force to be required to open the check valves for each circuit.
Confused yet? FOX has put together an informational video that might help make all of this easier to visualize:
Unlike a suspension fork, the way that a rear shock behaves is also influenced to some degree by the suspension design of the bike that it's installed on, which is why settings may vary between different models of bike. For this review, the Float X2 was installed on a Santa Cruz Nomad 3, which uses a 8.5” x 2.5” shock for its 165mm of travel.
Setting up the Float X2 begins with inflating it to the same air pressure as your body weight via the Shrader valve on the air sleeve and then slowly cycling it through 25% of its travel without removing the pump in order to equalize the positive and negative chambers. Once that's completed, it's a matter of adding or subtracting air pressure until the correct sag is achieved, and then using FOX's guide to dial in the base line settings for the two compression and two rebound adjustments. Turning the hex screw for each adjustment produces a satisfying click, which makes it that much easier to keep track of your settings. After that it's time for the fun part – actually riding, and tweaking rebound and compression as necessary.
For reference, my final settings at the end of the test were: • Air chamber: 170 psi • Low-speed compression: 20 clicks (all adjustments are from full closed) • High-speed compression: 21 clicks • Low-speed rebound: 21 clicks • High-speed rebound: 15 clicks • Volume spacers: 4
Those setting are quite close to the starting point that FOX recommends, with just a little bit quicker rebound and slightly less HSC on my part to reflect personal preferences.
Those black bands are used to reduce the air sleeve volume and increase the amount of ramp-up at the end of the shock's stroke, a simple process that doesn't require any special tools to accomplish.
On the Trail
Much of my time with the Float X2 took place in Whistler, BC, an ideal proving ground for any component due to the length and the steepness of the trails in and out of the bike park. The standout trait of the X2 was how well it handled high speed washboard sections of trail, the type of conditions that were common this summer due to months of dry and dusty weather. The shock made it seem like those repeated bumps had been covered by a layer of carpet – I could still feel them, but they weren't nearly as jarring and painful as they could have been, and the feel of the shock never varied no matter the length of the run. At slower speeds, the performance remained just as impressive, with plenty of suppleness to keep the rear end velcroed to the ground for maximum traction, and enough support deeper in the travel to prevent it from wallowing. Bigger hits never posed a problem either, and with four volume spacers installed there wasn't any harshness at the end of the stroke. In short, the Float X2 just plain works – there were no weird noises, no odd spiking or fading, just an incredibly consistent smoothness no matter what nastiness I rolled through.
RockShox's Vivid Air R2C is currently the most commonly seen DH-worthy air shock, so it makes sense to take a moment to compare it to the Float X2. The X2 weighs 90 grams less (for the 8.5” x 2.5” version), and has adjustable high-speed compression damping, which the Vivid does not. It's also easier to add or remove volume spacers on the Float X2 than it is with the Vivid Air. As far as on-trail feel goes, both do their jobs incredibly well, coming extremely close to emulating the feel of a coil sprung shock. However, I will say that I ended up preferring the feel of the Float X2 on the Nomad over the Vivid. It felt “sportier,” for lack of a better term, with just as much suppleness as the Vivid at the beginning of its stroke, but a slightly more supportive feel deeper in its travel, a trait that comes in handy when putting the power down to pedal through rough sections of trail.
The Float X2 is a highly impressive shock, with excellent performance out on the trail, and enough tuning options to satisfy even the pickiest of riders. The only thing that could make it even better would be a lever to quickly add compression damping when faced with a long climb, but by the sound of things this should be a reality sooner than later, although final timing and pricing have yet to be determined. When all is said and done, the Float X2 earns its place as one of the best gravity-oriented air shocks currently on the market, one that's capable of anything from World Cup downhill racing to rowdy all-mountain adventures in your own backyard. - Mike Kazimer