Polygon Bikes Siskiu N9 2019 Mountain Bike Review

Polygon Bikes Siskiu N9 2019

Reviews / Enduro Bikes

Polygon Bikes 65,099

At A Glance

Relatively unseen in Europe, Polygon have flown under the radar somewhat but are beginning to show us what we’ve all been missing over here, with some bold designs and some exceedingly well-priced bikes that have begun to get the market’s attention.

Buy Enduro Bikes on

Being the owners of their own factories means that Polygon is able to build bikes at a range of very competitive price points. A quick scan of their vast mountain bike range hints at a brand with financial clout and a blinding array of models to back up their aspirations to spark the imagination of riders around the world.

It’s perhaps no surprise that Polygon has gone hard with their Enduro bike offering, managing to pack in an eye-watering nine separate bikes into this category. Many will recall the striking looks of their futuristic XQUARONE range, with its NAILD R3ACT-2Play suspension system, but this is an entirely different beast. Not only is the suspension a classic single pivot, but the geometry numbers are far more contemporary. Hitting this more affordable price level we have the Siskiu range of Enduro bikes - a series of aluminium framed, long travellers, making use of a more conventional linkage set up.

Sitting atop this group is the Siskiu N9, available with 27.5” wheels up to size M, or as a 29er (as tested) with 160mm of front end might courtesy of a Fox 36 Rhythm fork and a Fox Performance Float DPX2 out back with three pedalling platforms: open, medium and firm. Geometry is geared towards big mountain riding, with 65 degrees on the head tube and an effective 75 degrees for the seat tube. Reach is much longer than previous Polygons we've ridden for the XL and sits at 485mm while the rear end sits on more than reasonably short 439.4mm chainstays.

With its chunky 36mm stanchion fork, 1255.3mm wheelbase, and aggressive 2.35” Schwalbe Magic Mary tyres the Siskiu N9 strikes a powerful set of lines and at €2999 comes with all the mod cons you could ask for: A 1x12 set up is handled by the ever capable and huge range of SRAM’s GX Eagle, while the dropper comes in the form of KS Suspension’s budget line 150mm Exa Form post. Further to this, some less commonly known parts appear in the form of TRP's robust and powerful looking Slate four piston brakes coupled to a pleasingly wide Entity XL2 Disc wheelset, all of which is polished off with a Truvativ Descendant Aluminium 32T narrow wide chainring and finishing kit from Australian brand Entity.

At first look, it appears that the N9 offers a great package and it’s hard to see how other bikes costing two or three times as much can compete with it.

On The Trail

What first strikes you when climbing aboard the Siskiu N9 is how roomy it feels, especially for riders over 185cm on the XL. The handlebars feel far enough away that knee strikes are out of the question, and with the 150mm seat post fully extended the pedalling position is balanced and solid, making climbing efficient. The steep seat angle means that the N9 climbs very well to the point of being surprisingly good, especially considering its descent-biased nature; the large wagon wheels keeping the momentum going over even the most jagged obstacles up the climbs.

Put some power through the pedals and the Siskiu’s frame remains stiff, transferring power to the wheels where the Schwalbe Magic Mary’s offer excellent grip and feedback and feel like they’ll never let you down when the going gets rough. The Fox Performance Float DPX2 deals very well with power transfer, never feeling overly spongy, and with the lever left in the middle position, it can be ridden comfortably on climbs as well as singletrack trails.

Given its length, Enduro-centric geometry and sturdy, if not hefty, weight, the Siskiu doesn’t scream of being a playful bike; this is a bike most at home when charging head on through roots and rocks or picking lines down steep technical lines, which it does reassuringly and with great poise.

Show the N9 a series of tight corners and it will start to laugh at you a little, yet this isn’t to say it won’t get round them - just don’t expect trail bike levels of lightness and handling when trying to flick it through the turns. The ability to get low down over that long front end and boss the 36mm Fox fork around definitely makes up for this lack of daintiness.

Thanks to the slack head angle confidence oozes through rock gardens and down large drops and the bike never feels overwhelmed when taking on repeated hits in some pretty testing terrain. This bike is made to make its rider feel like a king through Alpine-esque terrain while allowing them to still crank back to the top for another run.

The long reach and 150mm dropper mean that getting low down and forward is not a problem on this bike, offering stability and confidence. The chainstay length provides a good compromise between straight-line stability and cornering agility on all but the tightest of switchbacks, where the length of the rear end hampers turning progress somewhat.

The component list is clearly where the savings have been made, though that’s not to say that quality has been compromised. SRAM’s 12-speed GX Eagle, and the fork and shock from Fox all stand out as the great performers in this price band, and the strong Slate T4 brakes hold up over long descents, even if the reach adjusters have a tendency to unwind themselves and pull the levers towards the bar. The wide-rimmed wheels from Entity, when paired with the Schwalbe tyres, are a strong combination, offering confidence over roots, rocks and off camber wet trails, and really suit the bike’s confident demeanour. The biggest issues came from the KS dropper post, which after a couple of rides began to stick and misbehave despite efforts to keep it alive, and the Slate T4 brakes, which struggled with fade on sustained descents and in wet conditions.

Polygon’s paintwork and cable routing can’t be faulted (no doubt one of the benefits of owning your own factories and developing your own processing techniques). The frame itself displays a good mix of utilitarian might and modern refinement, with reassuringly strong looking joins and gussets between tubes and an elegant pivot point cover on the top linkage. Other nice touches can be found in the wrap around chainstay protector and neatly routed cables and cable access ports.


Bikes like the Siskiu are making it very difficult to justify parting with more cash for relatively small gains in rider satisfaction. The ride may not be the smoothest, out there, and the limitations displayed by some of the budget-end components may hamper the long-term riding experience, but these can all be upgraded in time. However, for what is a relatively small amount of money by modern standards, this is a hell of a lot of bike and the ability of the Siskiu’s rolling stock to put a smile on your face over rough terrain should not be overlooked.

Buy Enduro Bikes on

This review was in Issue 57 of IMB.

For more information visit Polygon Bikes


By Ewen Turner
Ewen Turner is a self-confessed bike geek from Kendal in the Lake District of England. He runs a coaching and guiding business up there and has a plethora of knowledge about bikes with an analytical approach to testing. His passion for bicycles is infectious, and he’s a ripper on the trails who prefers to fit his working life around his time on the bike.

Tried this? What did you think?