Bike Test: Polygon Siskiu T8
From relative obscurity a handful of years back, Indonesian-based Polygon has come charging through the pack to become a definite player in the mountain bike scene. Recently I tested the top-spec carbon Xquareone EX9 and, despite coming from a less well-known brand and its premium price tag, I consider it one of the best, if not the best, bike I’ve ridden to date.
There are two variants of the Siskiu T; the entry level T7 costs $2299, while our more premium offering, the T8, is priced at $2999. Both share the same 6061 aluminium frame, the same wheels and the same dropper post; both also run a 1x drivetrain. However, the T7 uses a 10-speed set-up, compared to the 11 speeds on offer with the T8.
The geometry of the Siskiu T8 is quite modern without being extreme. Our size Large test bike has a reach of 450mm, fairly short 435mm chainstays, a low 337mm bottom bracket height, and a decidedly slack head angle of 66.5 degress. Polygon has also gone for a scaled approach to wheel sizing, with Small and Medium bikes shod with 27.5-inch wheels, while Medium (as an option), Large and XL bikes come with 29-inch hoops.
This concept isn’t new, of course, but it does mean that the wheel size is more proportional to rider height, which helps to keep ride feel consistent across all sizes… and if you fit a medium you get to choose which way you want to roll!
In the Stand
Polygon has obviously put a lot of thought into the aesthetics of the Siskiu T8, and I think it’s hit the nail squarely on the head. The matte black frame with its orange and turquise highlights looks classy and understated. The lines are clean and the frame build looks beefy and ready to rumble. Welds aren’t quite as clean as on some other bikes I’ve seen, but they’re certainly not terrible, and it’s also nice to see solid pivot points with laser etched torque values on them, too.
It’s wonderful to see a set of wheels with a 29mm inner width fitted by Polygon, too; wide rims and wide tyres are definitely the way to roll, and the rims can be converted to tubeless with a bit of tape and sealant. It’s also unusual – and welcome - to see Schwalbe’s top tier casing and rubber on a bike at this price.
On the Trail
Not so long ago cheaper mountain bikes used to feel cheap, but not so with this latest Polygon. The thing that struck me about the Siskiu T8 almost immediately is just how much it feels like a much more expensive bike; it’s an incredibly neutral and intuitive beast to ride, with no learning curve or weird handling traits at all. Set sag (30 per cent rear, 22 per cent front) and rebound, and hit trails; that’s it. It pedals surprisingly efficiently even with the shock fully open, and it responds quite enthusiastically to pedal input.
On steep climbs the Siskiu sits quite deep into the rear travel which makes it light on the front end, so I deferred to the middle shock setting most of the time when I wasn’t pointed downhill. Pedal kickback is noticeable especially on square-edged steps, so some finesse is required to clean tricky climbs if you’re not clipped in. It’s not a deal breaker by any means, and no worse than a lot of other bikes on the market.
The bottom bracket height is very much at the low end of the spectrum, so I suffered a lot more pedal strikes than usual when climbing on the Siskiu T8; the trade off is in better handling through corners and more stability at speed.
In the open setting, the rear suspension strikes a good balance between suppleness and support; it doesn’t feel harsh at all, but it doesn’t use travel unnecessarily, either. The overall suspension feel is linear and progressive; in general trail riding situations it’ll rarely use the last 15-20 per cent of the shock’s stroke, and it’s only when you start hitting drops or gaps that you’ll see the travel indicator pushed to the end of the shaft. If you were hitting downhill lines regularly you might want to add a volume reducer, but otherwise the rear suspension is pretty much sorted straight out of the box.
At the other end of the bike I found the two air volume reducer tokens fitted to the fork made it almost impossible to access the full 140mm of travel, and I’d probably recommend removing at least one of them. Otherwise, the Revelation does a very good job of matching the performance of the back end, and in all but the most extreme (for this bike) or extended descents would you be able to pick a difference between it and the pricier Pike.
The only other point to note about the suspension is the slight amount of stiffening under brakes. This is common to most linkage-driven single pivot bikes, and you do get used to it quickly, but you can’t just come screaming into a corner full of braking ruts, grab a fistful of brake and expect to pull up smoothly.
Some might question why Polygon didn’t go with a Horst Link style of rear suspension (fitting a pivot at the rear of the chainstays) now that the patent has expired, but the advent of single ring drivetrains has made it easier to optimise the performance of a single pivot, and having one less moving part between the cranks and the rear axle makes for an inherently stiffer rear triangle. Swings and roundabouts…
It’s worth noting that the geometry of the Siskiu feels just about perfectly balanced for an all rounder mountain bike; it’s spacious enough for extended climbing, whippy enough for tight trails and stable enough to feel confident on the steep and relatively gnarly stuff. It corners very predictably, no doubt helped by the low bottom bracket, and it’s plenty stiff enough to track wherever you point it. It may well be a budget bike, but it certainly doesn’t feel like one once you get it rolling.
Polygon is like the musician who spends 10 years playing in pubs and clubs before becoming an “overnight” success. For 25 years Polygon has put in the hard yards, and suddenly the company has hit its stride. And everyone should sit up and take notice.
The Siskiu T8 comes in at a price that is very much at the entry level of the mountain bike spectrum, yet despite some budget parts it has no obvious chinks in its armour. It’s not perfect (see sidenote), but it looks good, it’s generally well built, has great geometry, excellent suspension, a good mix of totally functional parts, and there’s really nothing more you need to spend on it in order to get out on the trails.
Polygon blew my mind with the XQUAREONE, redefining the notion of the most capable mountain bike on the planet. Now it’s done the same thing with the Siskiu T8; it’s arguably the best performing bike on the market for the price, and probably better than a lot of bikes costing $1000 more. If you’re looking for a genuine, do-it-all mountain bike on a modest budget, this deserves to be at the top of your wish list.