What happens if you combine elements of Fox's DH-oriented Float X2 and the more trail-specific Float DPS shock? You get the Float DPX2, the newest addition to Fox's lineup, a piggyback style, air-sprung shock that's aimed squarely at the all-mountain / enduro crowd. Like the X2, it uses a twin-tube damper configuration, with independent rebound and compression adjustments. The DPX2 will take over the position currently occupied by the Float X, a shock that's been in Fox's lineup since 2013.
Fox DPX2 Details
• Twin tube damper
• Three compression damping positions
• EVOL air sleeve
• Weight: 499 (230 x 57.5mm)
• Price: $549 USD
Available in both metric and imperial sizes, the Factory series Float DPX2 retails for $549 USD. The 230 x 57.5mm version we have in for review weighed in at 499 grams, including mounting hardware. For reference, a Float X2 in the same size weighs 609 grams, while a RockShox Super Deluxe RCT weighs 529 grams.
There are three compression positions, with 10 clicks of fine tuning for the full open setting.
Look at that - a rebound knob that you don't need a toothpick to adjust.
The DPX2 has three compression damping positions – Open, Medium, and Firm, and on the Factory version there are ten clicks of additional adjustment that can be used to fine tune the feel in the Open position. The rebound dial offers 14 clicks of adjustment, and can be turned without requiring a tiny Allen key or a stick that you found on the side of the trail – a very welcome improvement over the Float X. Adjusting the shock's end stroke ramp up can be done by switching out the plastic volume spacer for either a larger or smaller one, a simple procedure that can be done without any specialized tools.
The DPX2 uses Fox's Extra Volume (EVOL) negative air spring, which is designed to improve small bump sensitivity by creating a more linear initial spring curve.
Along with a smaller piggyback for improved water bottle clearance, the amount of room around the shock's eyelet was also increased to help prevent any frame fit issues.
There are a variety of volume spacers available to adjust the DPX2's end stroke ramp up.
What's Happening Inside?
Where exactly is the oil going when the shock is compressed? I'll let the charts provided by Fox do the bulk of the explaining, but the gist of it is that rather than traveling back and forth along the same path, the oil in the DPX2 recirculates. The oil travels up to the Base Valve, through the compression and rebound circuits, and then returns via the space in between the inner and outer damper shafts. According to Fox, one of the benefits of this damper design is that it requires lower internal pressures, which improves the shock's small bump sensitivity. It also allows for more control over the rebound and compression circuits, helping to ensure that the shock can be configured to work well with a wide variety of suspension designs.
Reed Valve Lockout
When the DPX2's blue dial is set to the Firm mode, the oil is forced through a separate damping circuit that uses reed valves. A reed valve
blocks the flow of oil up until a certain amount of pressure is reached, at which point it smoothly opens up, acting as a blow off for larger impacts. In other words, if you somehow found yourself plowing through a rock garden with the shock in Firm mode, the ride feel will be firmer, but your fillings won't be rattled out of your head like they would be with a more traditional full lockout mode.
If thinking too much about oil flow, check valves, and piston velocity makes your head hurt, don't worry, you're not alone. The good news is that setting up the DPX2 is extremely easy – all that's required is adjusting the air pressure, and then dialing the rebound speed and the amount of compression damping in the Open position to your liking.
I'm running the DPX2 on a Trek Slash 29, and for my 160lb weight my current settings are as follows: 220 psi, 7 clicks of rebound, and 6 clicks of compression (rebound and compression are from fully closed), and the largest volume spacer. Of course, those numbers are just for reference – settings will vary widely from bike to bike, and every rider has their own preferences.
I'm just starting to put the miles in on the DPX2 – there are some long laps at Whistler in its future in order to see how it fares – but I've been impressed with its initial performance versus the Float X2 it replaced. The stock Float X2 had been a little tricky to get set up correctly on Slash
; at first, I was going through the travel more quickly that I wanted, even fully stacked with volume spacers, and it took a fair bit of experimentation before I was able to find my ideal settings. With the DPX2 I feel like I've found my happy place with much less tinkering, and haven't sacrificed anything in the way of performance. There's still plenty of range in the rebound circuit, and the same goes for the compression adjustment – it wasn't necessary to go to any extremes to get it to feel exactly the way I want.
So far the DPX2 has been silent and smooth, with excellent sensitivity on chattery section of trail. There's plenty of midstroke support for pushing hard into corners and remaining balanced on the steeps, and there haven't been any harsh bottom outs despite my best efforts. The DPX2 also delivers a very smooth feeling when landing, and whether that's after hitting a jump or bunnyhopping a section of roots, there's absolutely no harshness – the shock responds extremely quickly, taking the edge off and providing a buttery smooth touchdown. I've been using the full open mode for descending, but the Medium and Firm compression modes are both very usable – the Slash is a fairly active bike, so I've been taking advantage of the Firm mode for longer, smoother climbs, and using the Medium mode on more technical ascents in order to take advantage of the increased traction.
I'd imagine we'll start seeing the DPX2 show up on everything from shorter-travel aggressive trail bikes all the way up to full-blown enduro race machines – the range of sizes and stroke lengths makes it a very versatile option. Stay tuned for a long term review, as well as a comparison to other shocks in this category.