Polygon Xquarone

Let’s be frank; Polygon is certainly not the brand that comes first to mind when you think about high-end bikes. The Indonesian company has been on the local scene for about 10 years now but has previously pitched itself at the budget to mid-end of the spectrum. That’s set to change with the arrival of the XSQUAREONE, a totally new design pitched as a one-bike solution for everyone except hardcore DH and competitive XC riders.

Designed for 27.5 inch wheels, there are two variants of the XQUAREONE available with prices of $6,999 and $8,499 for the EX8 and EX9 respectively; like I said, these are serious high-end propositions. Both use the same full carbon fibre frame and suspension design, with the components being the only distinction between the two.

Our EX9 test bike came with the best of the best; Fox 36 Factory fork and Float X2 shock, SRAM XX1 Eagle 12-speed drivetrain, SRAM Guide Ultimate brakes, E13 TRS Race Carbon wheels, Schwalbe Nobby Nic tyres in a generous 2.6 inch width and the list goes on.

It’s a bike with no real upgrade requirements, which of course is what you’d expect given the price tag. Despite its 180mm of travel, our large sample weighed just 13.83kg without pedals; no race whippet, but certainly very reasonable given the burly components and amount of travel on offer.

Polygon Xquarone

The XQUAREONE features a new suspension design called R3ACT, licensed from Darrell Voss of NAILD suspension, and despite its 180mm of travel it’s claimed to pedal like a short-travel trail bike. Of course we’ve heard that claim many times before, but mountain bikes have also never seen a suspension design quite like this before, so I was determined to keep an open mind and reserve judgement until after riding it.

The build quality and finish of the XQUAREONE is a big step up from anything we’ve previously seen from Polygon; they’re clearly serious about mixing it with the big players in the MTB scene. Some riders will be disappointed by the lack of water bottle mounts, but in other respects it doesn’t leave anything out; ISCG tabs, good standover clearance, short 425mm chainstays, a generous 462mm reach, bolt-on rock guard and boost hub spacing are all on point.

The head angle of 66-degrees isn’t as slack as you might expect, and the bottom bracket height of 354mm is very tall by comparative standards, but given that it’s intended to be pedalled uphill as much as raced down, those numbers start to make a bit more sense.

Polygon Xquarone

The KS dropper post fitted (125mm on medium frames, 150mm on L-XL) uses a custom offset head to maintain the desired seat tube angle. That said, the stock angle is only 73.5 degrees, so if you wanted to use a different post with an inline head you’d still only be in the 75-76 degree range, which some riders (including myself) actually prefer.

The rear thru-axle is a new Darrell Voss design; you press a small lever to unlock it, then give it a quarter turn and slide it out. It’s pretty quick and slick once you get the hang of it, but to be honest I prefer the simplicity and foolproof reliability of a screw-in axle like the Syntace X12 design.

Aesthetically, the big Polygon is pretty polarising; it certainly doesn’t look anything like the classic twin triangle bike frame and there are many complex shapes around the bottom bracket area before you even get into the chunky, elevated swingarm. Whether you love or hate it, this is a bike where form follows function; every one of those bends, kinks and oversized tubes is there for a specific purpose, which is to accommodate the rear suspension.

Polygon Xquarone

So how is the suspension so different? At its heart, R3ACT is a short link four-bar arrangement, but instead of the lower link being the ‘primary’ link, in this case, it’s the upper link which takes that title. More significantly, perhaps, is that the lower link doesn’t just pivot, but slides as well; it’s a long stanchion that resides within the oversized rear swingarm and pivots near the bottom bracket.

There’s no damping of any sort in this sliding member, and although it’s not the only sliding link suspension system on the market (Yeti’s Switch Infinity is another), it certainly takes the concept further than anything else currently available.

The R3ACT suspension has another key design principle; it relies almost solely on the suspension kinematics for pedalling efficiency. There’s no pedal assist lever, and the Fox shock apparently has around 60% less damping than the previous lowest damper tune from Fox.

Voss is adamant that relying on damping and clever shocks to counter pedalling forces is a fundamentally flawed way to view suspension; it effectively stifles the ability of the rear wheel to track the ground properly, so you lose traction both uphill and down. I’m inclined to agree with that idea, so it was with somewhat piqued interest that I took the XQUAREONE for its first spin on one of my local old-school DH trails.

Earn your Turns

The ride commences with a 20 minute climb up the 'old-old' DH track; there are no gap jumps and only a few larger (50cm) steps, but it’s consistently steep, rocky and twisty. It’s the type of trail which very quickly tests the traction and climbing prowess of any bike, not to mention the rider’s legs!

There are plenty of short travel bikes that struggle with it and I have to say the concept of approaching this climb with 180mm of travel and no climbing aid from the shock was a bit intimidating. 

I shouldn’t have worried; from the very outset it became evident that the XQUAREONE is not like other bikes. It pedals more efficiently than any 160mm travel bike I’ve ridden and many 130mm travel bikes would struggle to outperform it. I’ve seen a few reviews that claim it pedals like a hardtail; whilst that’s not really the case, nonetheless, it has very close to zero unwanted suspension movement whether in or out of the saddle.

Given that the bike is intended to do a lot more than just descend confidently, I think the designers at Polygon did well by avoiding the ‘lower is better’ trend.

I’ve already mentioned that the XQUAREONE has a steeper than expected head angle, but again this helps a bit in keeping the wheelbase from getting too long and the steering too slow. Combined with the relatively short 425mm chainstays, I had no problem getting the green beast around uphill switchbacks and threading through tight, twisty, tree-lined sections of trail. There’s no doubt that the Polygon is happy at speed, but it doesn’t need to be going fast in order to be fun, unlike some slacker/longer bikes which are quite unwieldy at low speed.

Runtime Funtime

Anyway, at the top of that 20 minute climb, you get to turn around and point downhill for five minutes or more on a trail with plenty of elevation loss, a few decent step-downs, a couple of gap jumps and one very rocky steep and eroded chute. There’s a series of sweeping, ever steeper downhill turns leading into that chute, and as I pumped through them I remember thinking to myself that I hadn’t gone this quickly on this section of trail on any other bike in recent memory.

My innate sense of self-preservation kicked in and I squeezed the brakes a few times to milk off some speed, but the XQUAREONE was completely composed and stable—had my courage been greater I’m sure I could have gone even faster still without it getting rattled in the slightest. Picking lines over and around those embedded boulders still had me going faster than ever before and the only thing that slowed me towards the end was a pinch flat as a cased one of the last rocks after a small but steep drop-off. Yep, the XQUAREONE can go downhill, and fast!

Polygon Xquarone

The limpet-like ability to follow the terrain which I experienced climbing is also present when descending; the R3ACT suspension does an outstanding job of smoothing out bumps of all sizes so you can focus on picking your lines and not worry about your teeth being rattled out or your feet getting bounced off the pedals.

I’d say the suspension feel is moderately progressive, and although I’m not going to be entering Red Bull Rampage any time ever, it resisted bottoming over repeated solid hits and six-foot step downs—aside from huge hucks there’s little if anything the XQUAREONE won’t be able to take in its stride.

Make no mistake; Polygon’s XQUAREONE is a true modern superbike, and it goes as close to the one-bike quiver as anything on the market. If this is their first attempt at combining the R3ACT suspension with their extensive but previously more modest manufacturing expertise, there’s going to be a lot of other, better-known brands quaking in their boots at the thought of what Polygon comes up with next.

Polygon Xquarone

Despite its high entry price, if you want just one bike to do just about everything, and without compromise up, down or along the trail, this is the bike to get. Seriously.


Surreal ability to combine climbing efficiency and descending prowess

Impressive spec and build weight

Not boring to ride on more sedate trails


Could be a tad slacker if truly high-speed and super steep trails are your thing

Polarising looks


Frame Full Carbon Naild Suspension

Shock Fox X2 Factory 180mm Travel

Fork Fox 36 Factory 180mm Travel

Headset FSA Orbit Sealed Bearing

See the full post.

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