Tested: Polygon Siskiu T8 - FLOW

Polygon Siskiu T8

What am I looking at here?

This is a thoroughly modern trail bike, made affordable. You can grab the Siskiu with either 29″ or 27.5″ wheels, with 140mm or 150mm respectively, though depending on your frame size you might only have one option. In a size small, it’s 27.5” only, sorry shorties. In a size medium you can get either wheel option, while in a size large or XL, it’s 29er only. We’ve been riding a size medium in 29er.

Where can I see one?

This is where it’s a bit tricky. Polygon are sold online, direct to consumer here in Australia, so waltzing down to your local shop for a carpark bounce won’t happen. The bike is shipped to you 99% assembled, requiring just a few things to be done before you head to the trails. For some people, this will be a deal breaker, but it’s the price you pay for not paying much of a price, if you get our drift. The bike does come with a money back 14-day test ride period.

Siskiu T8 Wheels

All the Fundamentals are there

On paper, Polygon have nailed it. Modern geometry? Tick, it’s got the geometry numbers that stack up nicely with the competition, and the dropouts have Boost spacing too. A confidence inspiring front end? Yep, there’s a 35mm-legged fork, and a wide bar and short stem. Dropper post? Yes, a 150mm dropped is ready for the steep stuff. Good rims and rubber? Indeed, 29mm internal rims give a Schwalbe tyres good stability. A single-ring drivetrain? Yes, once again the Polygon is up to speed, with a 1×11 drivetrain

A Few Compromises

To hit such a sharp price point and still deliver those items above, Polygon have saved a few bucks in some other areas – the crankset is from Prowheel for instance. The Tranz X dropper post isn’t one we’ve ridden before, and while it works nicely, the lever feels a bit flimsy.

It’s not overly refined either; the cables rattle inside the frame quite a lot (you can fix this by placing some foam rubber inside the frame), and the welds are a bit chunky. But, of course, none of these issues have a big impact on the way the bike rides.

Siskiu T8 Handlebar

That is the story on paper, but what about on the trail?

It took us a couple of rides to find our groove with the Siskiu. Long story short, it’s a bike that has a sweet spot. We found that suspension setup and tyre pressures made a big difference on this bike and until we got this right, it all felt a little chattery and tiring in the rough.

Tubeless First

First up, we converted the Siskius wheels for tubeless use. You’ll need to add tubeless tape to the rims first as they’re not set up for tubeless use out of the box. This is a must-do. The Schwalbe tyres are a hard compound, so you really need to ditch the tubes and drop the pressures or they tend to skate around on hardback trails. A set of stickier tyres would be a great upgrade for this bike, helping glue it to the trails more firmly.

Get that suspension working for you

In order to help get the bike feeling as smooth and composed as possible, we spent more time than usual making fine adjustments to the suspension. Ultimately, a softer suspension setup and a moderately fast rebound speed was the best approach for this bike. Set up like this, the suspension stays nice and active which helps the bike hold speed better in the rough and gave us a lot more grip in the corners. With the fork, we actually removed one Bottomless Token from the air spring and followed the recommended pressure.

Siskiu T8 Suspension

Strong Position

Once we had all that sorted, the bike became a lot easier to get along with and suddenly we found our groove with the Siskiu and we began taking it to all our usual haunts, banging through the rocks around Flow HQ. The riding position is great; the wide cockpit and stout fork put you in a strong and commanding position, encouraging you to take control, and 140mm travel will get you out of trouble most times. It’s exactly the kind of feeling you want if you’re an intermediate rider losing to push your skills to the next level.

Siskiu T8 Fork

Impressive Efficiency

Given the price, the sub-14kg weight is pretty damn good. Pedalling performance was a surprise standout element for us too – it’s a really stable pedalling bike. The shock has a three compression settings (open, firm and locked) but we rarely flicked it out of the open position. It’s certainly happy to trundle through a few hours on the trail without draining you too much – it’s way more efficient in this regard than we expected.


There’s a fair bit of cable rattle going on, and there aren’t any water bottle mounts. The seat angle is slack too, and we needed to push the saddle forward in the seat clamp to feel like we were in a good position over the cranks. Tall riders with a lot of seat post out might find themselves pushed out over the rear wheel quite a long way.

Polygon SIskiu T8 Dual Suspension Mountain Bike

Hard to top for this money

This is exactly the kind of bike that’s going to make mountain biking (real mountain biking, not just cruising in the bush) accessible to a much bigger audience. Three grand is eminently more achievable than five or six grand, and the compromises this bike makes to hit such a good price point really are quite minimal.

Once you’ve invested the time to get the suspension set up perfectly (and maybe added some stickier rubber once the stock tyres are worn out) you’ve got a bike that comes very close to matching the performance of bikes with much higher ticket prices.



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