This month’s new bikes on the block include the innovative Polygon Xquarone EX8, the race-ready NS Fuzz 1 downhill bike and the nimble-handling Cube Stereo 150 C:68 TM 29
£6,400 It’s no looker, but does its innovative design give it an edge?
The defining characteristic of this bike is its radical rear suspension. It’s the brainchild of a company called Naild, and has di erent ride characteristics to any other system out there. Despite its 180mm of travel, the Xquarone (“square one”) is claimed to pedal superbly, making it a versatile all-mountain bike.
The frame
While the carbon fibre mainframe is designed by Polygon, the swingarm (also carbon) is supplied by Naild, but is specifically designed to work with this bike. It slides up and down on a large cylindrical stanchion, which connects to a main pivot just in front of the chainring. The path of the rear wheel is controlled by this stanchion, along with a pair of rotating links which connect it to the frame higher up (and improve rear end sti ness). Large bushings and seals minimise friction. The suspension is controlled by a Fox Float X2 shock with a light damping tune.
The kit
It may be the lower-specced of the two Xquarone models, but the EX8’s components leave little to be desired. Fox’s 36 FIT4 is one of our favourite forks, while SRAM’s X01 Eagle gearing provides all the range and refinement you’ll ever need. The Guide RSC brakes perform well too, though, on a bike of this travel, we’d like a bigger front rotor. Our only real complaint is with the KS LEV SIO dropper, which has a layback head that e ectively slackens the seat angle – we’d prefer an inline post.
The ride
The most impressive thing about this bike is how it pedals. Forget how much travel it has – no matter the gradient, cadence or power output, the suspension is completely stable when seated. That means it surges up sat-down climbs with almost hardtaillike e ciency. When sprinting out of the saddle, there is a little suspension bob, but less than on most mid-travel trail bikes. Normally, bikes that climb e ciently sacrifice some suspension sensitivity. Naild system is di erent. The Xquarone’s well-balanced anti-squat, near-vertical axle path and light shock tune give it a supple, almost ‘floating’ feel on bumpy trails that keeps it comfortable and stops it hanging up on the faces of obstacles.
Interestingly, this isn’t what we found with Marin’s Wolf Ridge (MBUK
350), which uses its own variation of Naild’s ‘R3ACT’ system. That bike had a more jarring ride, especially when pedalling. The di erence could be down to the Polygon’s extra 20mm of travel, its shock tune or its slightly di erent suspension kinematics. We also found that the Marin’s back end flexed so much, laterally, in certain situations that the shock would bind. The Xquarone appears to be sti er, both when wiggling the rear wheel from side to side and when riding. We didn’t notice any binding during our testing.
The Polygon works best with a firm spring rate (around 25 per cent sag). We left the compression damping fully open and the rebound a little faster than normal. When descending, the suspension was impressively reactive over repeated rock hits, encouraging the rider to drop their heels and allow the bike to do its work. The rear wheel moves up and over objects with very little fuss, and the bike maintains momentum through bumpy sections brilliantly.
On the flipside, the sti y-sprung and lightly-damped suspension makes for a less than settled ride in steep, steppy sections, and becomes unreactive when the rear wheel is locked up. Heavier riders may want more pressure in the shock than the 250psi Fox recommend (at 85kg, we ran 240psi). The rear axle also worked loose, and was a pain to refit.
Where the Xquarone really comes unstuck though, is with its geometry. The slack 73.5-degree seat angle and layback post put the rider’s weight too far back, making steep climbs awkward. Fitting an inline post would help, but would make the cockpit – which is already short by modern standards (the XL we tested had a reach of 471.4mm) – feel cramped.
When descending, the short front centre, relatively steep (for the travel) 66-degree head angle and high spring rate push the rider’s weight forward, making for a nervous ride on steep trails. We had to run the fork harder than normal and ride over the back more to compensate. This made the Polygon tiring on prolonged rough descents. SEB STOTT www.polygonbikes.com