Polygon's XquarOne EX
attracted all sorts of attention when it debuted in the spring of 2017, and for good reason. The otherworldly frame design stood out from the ever-growing crop of four-bar lookalikes, and its performance on the trail was out of the ordinary as well. It wasn't long before members of the Polygon UR team were spotted riding DH bikes with a similar suspension layout as the XquarOne EX, and semi-camouflaged prototypes started appearing at Crankworx and World Cup events around the globe. That bike, called the XquarOne DH, is now ready for public consumption, with two complete models and a frame-only option hitting the market.
XquarOne DH Details
• Intended use: downhill
• Wheel size: 27.5"
• Rear wheel travel: 218mm
• Carbon frame
• 63° head angle
• 440mm chainstays
• Super Boost 157 rear spacing
• Sizes: S-XL
• DH9: $6,399 USD, DH8: $4,999 USD
29” DH bikes have been a hot topic this season, but Polygon chose to go with 27.5” wheels for the XquarOne DH, stating that they were focused more on creating a bike that was fun to ride, and wasn't strictly for DH racers. Now, whenever I come across a marketing pitch that supports the idea that 29” downhill bikes aren't fun to ride I tend to roll my eyes, mainly because it's an antiquated notion that wheelsize has any relation to the level of enjoyment delivered by a bike, but that's a topic for another time. Big squishy DH bikes are fun no matter what size wheels they have. Anyways, back to the XquarOne DH.
Along with 27.5” wheels, the bike also has 218mm (8.6”) of rear travel that's delived via the Snuffleupagus-looking NAILD R3ACT suspension layout. The suspension configuration is relatively the same as the XquarOne EX, but the shock tune was developed with the rigors of downhill riding and racing in mind.Frame Details
The XquarOne DH's frame is carbon from tip to tail (excluding the rocker links and the stanchion that the swingarm slides on), part of the reason Polygon were able to keep the weight down to a very reasonable 8.8 pounds, including the shock.
Super Boost 157 spacing has begun to pop up on a handful of trail and enduro bikes, and it also makes an appearance here on the XquarOne DH. That means there's a 12x157mm rear end matched to BB92 bottom bracket, rather than the BB107 or threaded 83mm bottom bracket shell that you'd typically expect to find on a DH bike.
The rear brake and derailleur housing are tucked away inside the frame, emerging only briefly to bridge the gap between the front triangle and the swingarm. The frame's unique shape leaves a lot of surface area exposed in front of the bottom bracket shell, so Polygon installed a thick plastic protector to keep the bike's underbelly safe from rock damage. There's also a fender attached to the swingarm, complete with a label warning that the bike isn't to be ridden without the fender in place. Suspension Design
If you're unfamiliar with the NAILD suspension design, here's the basic rundown. The swingarm is attached to the front triangle by a short aluminum link, and the shock is driven by a yoke that wraps around the seat tube. That description would work for a number of dual-link designs, but there's one more element to this system – an aluminum stanchion tube that the swingarm slides over. No, it's not another shock, just like the two short rods on Yeti's Switch Infinity design aren't tiny shocks either. Instead, this layout allow for the bike to have a consistent amount of anti-squat (between 98 – 110%) throughout the entire gear range. In theory, that means the bike should still pedal well even if you're at the bottom of the cassette and need to throw in a couple extra pedal strokes to get speed for a jump, or putting down the power for a final sprint to the finish line.
The NAILD design works best with a shock that has a very low amounts of compression and rebound damping, and in this case a custom tuned Fox Float X2 gets the job done.Geometry
The XquarOneDH's geometry numbers fall right in line with what you'd expect from this style of bike – it has a 63-degree head angle, 440mm chainstays, and a reach of 450mm for a size large. Standover height remains the same for all four sizes, which makes it easy for riders looking for a little extra length to size up. The lack of an XXL may have the tallest of riders looking elsewhere, but as it is the four sizes should cover a wide range of heights. Build Kits
Along with the two complete bikes, the DH9 and the DH8, Polygon will also offer the XquarOne DH as a frame only option for $2,999 (including the Fox Float X2 shock), or it can be purchased with a Fox 40 Float fork for $4,399.First Ride Impressions
In a perfect world, this would be where I'd describe the nuances of the XquarOne DH's handling, and report on how it's been holding up to long days in the Whistler Bike Park. Unfortunately, that plan didn't really work out the way I'd hoped, and I've been on the injured reserve list for the last few weeks.
However, I did get in a couple of laps in the park before being forced to the sidelines, laps that made one thing abundantly clear: the XquarOne DH delivers an incredible amount of traction, especially while cornering. Typically, it's pretty easy to let the back end get drifty when summer is in full swing and the trails are dry and dusty - all it takes is a subtle weight shift in the right scenario and the rear wheel of almost any bike out there will break free and slide around like a gymkhana car. With the XquarOne DH it's a different story – that rear tire feels absolutely glued to the ground, no matter how hard you push into it. It's a wild feeling, one that quickly leads to increased confidence when heading into a sharp turn with a good head of steam.
That massive amount of traction had me expecting to need to fight to get airborne, but the XquarOne responded relatively well. There's not as much pop as you'd find with something like a YT Tues, but it didn't take a massive amount of effort to take flight either. My abbreviated stint on this bike left me with plenty of unanswered questions – I'm curious about how the bike will feel in really rough, choppy terrain, and about how the swingarm elements will fare when it comes to durability, but I'll need more time on the bike before I can figure out the answers.