TESTED: 2024 Polygon Siskiu T6 trail bike

The Polygon Siskiu range must be one of the most popular models in Australia, and likely a key bike to get people out on the trails, along with ranges like the Giant Trance and Trek Fuel EX. Sold exclusively via BikesOnline, the Siskiu range has always been split into the D, or downcountry range, and T – the trail range. This year we have also seen two e-bikes added to the trail range, and I recently reviewed the very impressive Polygon Siskiu T6E e-bike.

The D series have 120mm of travel front and rear, whereas the T series as tested here have 140/135mm travel split on the 29ers, and 150/140mm on the small and medium 27.5" wheeled bikes. This also has an impact on the geometry, and Polygon spec parts appropriate for the use of each range of bikes.

The Siskiu T6 is a new lower priced model in the Siskiu trail bike range, selling for $2299 however it is built on the same frame as the higher end T7 and T8 models that sell for $2899 and $3899 respectively. The idea is to get riders on the trails for less, without impacting the handling or quality of the bike. At this price the Siskiu T6 is $700 less than a Giant Stance 29, but with a similar parts kit and more travel. It really does play in its own patch of the dirt.

Photographer: Gerard Lagana
Tester: Mike Blewitt
Riding Experience: Lots of travel to ride, race and explore places by bike
Generally Rides: Factor Lando XC
Height: 178cm
Weight: 72kg
Bike Test Track: Brisbane trails

Initial Impressions

The Polygon Siskiu T6 was delivered to my front gate, which is what you can expect for any Polygon from BikesOnline. This is a direct to consumer business, so you buy your bike via the BikesOnline website. You need to choose your size, any accessories, pay your money and your bike will be delivered. You'll need to sort out sizing yourself, but BikesOnline have plenty of guidance on their website and via their customer service line. Bear in mind that Bikes Online have a 14 day free returns policy if you unbox the bike and realise it's not for you. More details are on their website.

The Polygon Siskiu range is one of a few on the market that has stuck with size specific wheel sizes. So while small and medium Siskiu T6 models come with 27.5” wheels and 150/140mm travel, the 29ers are available in medium, large and extra large. The 29ers come with 140/135mm travel. So if you're a medium-ish size, you'll need to decide if you want the agility and touch more travel of the 27.5” wheeled bike, or the big-wheeled approach of the 29er. I had a large on test which I find suits my 178cm height and lanky arms.

We have tested a number of Polygon bikes recently, and while their value has been a stand out, what has really impressed us has been how balanced the ride is. The geometry is a key component for this, along with suspension. The large Siskiu has a reach of 480mm with a head angle of 65.5 degrees. While it seems quite long, Polygon do use a short 35mm stem and a steep 76.5 degree effective seat angle. This means you're nicely centered between the wheels, which aids in weight balance climbing, descending and working the bike in turns.

The frame has internal routing through the main frame, and room for a bottle cage. There's room for 2.6” tyres, plus there are ISCG mounts on the threaded bottom bracket shell if you'd like to run a chain guide. The swing arm isn't UDH to be compatible with SRAM Transmission group sets, but that is unlikely to be a worry for those looking at a $2299 trail bike.

The build kit is pretty solid for the price, with parts similar to the hardtails around $1600-2000 we tested in early 2023, but on a full-suspension bike. Shimano take care of the drivetrain and brakes with 10-speed Deore and MT200 2-piston brakes with 180mm rotors. A 140mm RockShox Recon does fork duties while an X-Fusion O2 Pro R sorts out the back. There's a smooth TransX dropper, and wide Entity rims supporting Vee rubber – although you'll need tubeless tape, valves and sealant to get setup tubeless. Entity provide the bars, stem and grips – and they're all great although a bit more sweep would be nice.

Once built, my test bike clocked 17.43kg before I fitted pedals and a cage. It's no fly weight. A lot of this weight is in the wheels, but that's fine. Polygon have specced wheels with reliable hubs, 30mm internal widths and high volume tyres. These all add up to great capability for trail riding, along with strength – the trade off is weight. But you can't have everything for $2299 – although with the Siskiu T6 you sure do get a lot.

On The Trail

The last Siskiu I tested, besides the T6E e-bike, was the 120mm Polygon Siskiu D6. I really liked it for what the bike offered at just over the $2000 price point. I did find a couple of things held the bike back, primarily in suspension and crank length. The former was a complaint about a basic fork that wasn't supple enough and was overdamped, and the latter impacted pedal clearance even on fairly non-technical climbs. With the longer travel but similar budget T6 on test, I was curious to see how the bike would ride given that it was such a great entry-level price for a trail bike.

Climbing away from the trail head I was rewarded by a stable pedalling bike, which is good as there is no external compression damping – just air pressure and rebound. You'd be wise to invest in a shock pump when purchasing a T6 as you'll need it to get the most out of the bike. But that goes for any bike with air springs. Sitting and spinning away the rear shock was stable enough, finding traction on fire trails and singletrack alike. I set the bike at 25% sag as I know I prefer a slightly higher position on the trail.

The fit was really good, with the 480mm reach and reasonably low cockpit height being exactly how I like a trail bike to fit. Those who prefer a more upright fit may like to fit a higher rise bar, which would provide a good opportunity to fit something with a little more sweep as well. As is, I found the fit was great at keeping the front wheel tracking on the climbs and through corners, although a bit of a weight shift was needed on steep pinches to stop the front from wandering.

With a 10-speed Shimano 11-42 cassette and 32t chain ring the T6 gets up hills but it sure doesn't come alive when climbing. There is no way around the fact that 17.5kg of bike isn't a tonne of fun to fight gravity with. It does the job and rewards sitting and pedalling, with the suspension being a bit too active to really get out of the saddle and jam on the pedals. All this blurs into the background when you crest a climb.

The geometry and fairly stout frame of the T6 work hand in hand to be an active yet suitably stable ride on even the most shallow of descents. With a 430mm chain stay length on the large 29er the Siskiu T6 remains quite agile, especially with the rapid steering response with a short stem. Throw in burly wheels and tyres and a big foot print, and you have a bike that is plenty of fun to descend on. The Siskiu pops over features with more condifence than you may expect for a bike that only costs a little more than $2000, and it rewards sighting launches and landings on the trail.

With a slack 65.5 degree head angle and 480mm reach the Siskiu is stable at speed, but not as stable as it could be thanks to the shorter back end. But as a 140/135mm travel trail bike I think the balance between the two is just right. If you want a big hit bike for hitting top speed in chutes, get something like the Polygon Collosus. The Siskiu is a trail bike and I think it walks that line really well.

The RockShox Recon fork is simple but adequate. It ran stiction free and the damping works. I did have to run far beyond recommended pressure to have it support the riding I was doing – and I'm not an aggressive rider. But given it is an air spring, this is an easy adjustment to make. It is worth remembering that the T6 frame is the same as the rest of the range, the bike could support a suspension upgrade for the shock and fork if you wanted to. It is built well and has the handling for it. But as is, I had fun with the stock build.

On steeper trails out with some of the test crew I did find my own limits and that of the bike more often. On steep, loose trails where you need a rapid brake response and precise suspension to find traction and composure, the Siskiu and I were out of our depth. The basic 180mm rotors and two piston brakes meant I couldn't let the bike run as much as I may like on steep terrain, as I knew I wouldn't be able to pull it back in. And on longer rockier sections the linkage driven single pivot design wasn't really working as well as it did from single big hits as it was under braking far more often. This should be no surprise, as the trails were steep, rough and tight – not really the remit for an entry level trail bike.

While the Siskiu frame design offers lots of standover height, on these very steep trails I did wish for a longer dropper post, but I think this is still pushing to the extreme for the intended use of the Siskiu T6.

Our Take

The Siskiu range has always been popular and the new T6 means it will suit more people than before. The $2299 trail bike brings trail capable builds in the Siskiu range to a lower price point, reflecting just what many people want in their new bikes. Like so many of the Polygon bikes we have reviewed recently, the ride quality and handling is far beyond what you may expect for the price point – you'd easily think you were riding a bike worth a lot more. This is a huge bonus for riders looking for a trail bike at around $2000 as you get a truly functional bike with room to make some improvements.

On most of my local trails I found the Siskiu T6 fantastic fun for the money. Sure, it's heavy but that comes with the territory. On steeper trails the brakes were a bit light on, and on repeated, heavy hits the suspension can get a little overwhelmed. But this isn't an enduro bike – it's an entry level trail bike that really punches above its weight. If you want some better braking, shifting or suspension performance check out a higher end model in the range, The T7 gets better brakes and suspension if you know you'll want that from the get go. Or make some specific upgrades over time, and go get on the trails right now.

If this were my bike I'd make sure I had an accurate shock pump to get the suspension dialled in, I'd fit a tubeless kit to increase traction and handling, and I'd consider a new handlebar with more sweep, and perhaps a pad and rotor upgrade to bump up the braking power. As it is though, the Siskiu T6 is going to make a lot of people happy on the trails.

Full specs on the Polygon Siskiu T6

RRP $2299
Weight 17.34kg (as tested)
From bikesonline.com.au

Available Sizes S, M, L (tested), XL
Frame Material Aluminium
Fork RockShox Recon, 140mm
Shock X-Fusion O2 Pro R, 135mm

Shifter Shimano Deore 10sp
Derailleur Shimano Deore 10sp
Crank Shimano, 32t, 170mm
Chain KMC X-10
Cassette Shimano 11-42t, 10sp

Hubs Shimano MT400, Boost
Spokes Black, stainless
Rims Entity, 35mm inner
Tyres Vee Snap WCE Mk2, 29 x 2.5”

Brakes Shimano MT200 2-piston 180/180mm
Stem Alloy 35mm
Handlebars Alloy 25mm rise, 780mm
Seatpost TranzX, 170mm
Saddle WTB Volt