Is The Polygon Siskiu T8 The Best Budget MTB?

The 2025 Polygon Siskiu T8 proves that you don’t need to spend big to get a capable, modern trail bike. Priced at $3,799, this 140mm/135mm travel 29er continues Polygon’s reputation for delivering affordable mountain bikes that punch well above their weight.

There’s one thing that’s happened since I took on this role that was somewhat unexpected – and it’s the opposite of bike snobbery. While it’s true that all our contributors ride fancy, expensive bikes (after all, bikes are our lifeblood!), my experience testing bikes has broken down my own elitism – thanks in large part to the Polygon Siskiu range.

We’re no strangers to the Siskiu here at AMB – the affordable 140mm/135mm alloy 29” trail bike that punches well above its price tag. The new 2025 Siskiu T range has just been released, and while it’s more of an evolution than a revolution, it highlights Polygon’s commitment to staying current. Updates include Shimano brakes across all T-series models, UDH frames with reinforced rear triangles, top tube mounts, internal cable routing, and modernised geometry.

A few years ago, I wouldn’t have been excited to jump on a sub-$4000 trail bike. But after riding earlier Siskiu models, I felt that familiar buzz of excitement heading out on a bike that’s not only affordable by today’s standards, but also promises to deliver a seriously fun ride.

We have a Polygon Siskiu T8 on test – the top-tier model in the range – retailing at $3,799. For riders on more of a budget, the Siskiu T6 comes with a RockShox Recon Silver RL fork, X-Fusion O2 Pro R rear shock, Shimano Cues 1×10 drivetrain, and Shimano BL-MT200 2-piston brakes, retailing at $2,599. The mid-tier T7 also features a RockShox Recon Silver RL fork but upgrades to a RockShox Deluxe Select+ rear shock, Shimano Deore 1×12 drivetrain, and Shimano BR-MT420 4-piston hydraulic disc brakes, retailing at $3,099.

First Look

Sent directly to my house by BikesOnline, the Siskiu T arrived in a massive box, pre-built and needing only minimal setup before hitting the trails. Tubeless-ready wheels and tyres are a win, and we were impressed to see Polygon spec Maxxis Dissector 29×2.40″ tyres with 3C MaxxTerra Compound and EXO+ Protection.

Polygon states that they’ve reduced bulk by using their Polygon MT6 alloy rims paired with Shimano hubs – a welcome upgrade with a claimed 200g wheelset weight reduction. Both the Siskiu T8 and T7 models also feature these upgraded hubs. Riders familiar with previous Siskiu generations will know the value has always been excellent, but the trade-off was often heavier wheelsets that made acceleration feel a little sluggish.

The Siskiu T8 runs a predominantly Shimano SLX drivetrain with Deore cranks. We were delighted to see Shimano 4-piston brakes now featured on the T8, as earlier generations features Shimano drivetrains with TRP brakes.

Previous Siskiu models walked the line between being planted and poppy, but they sometimes showed their limits when things got rowdy. Polygon appears to have listened to rider feedback, reinforcing the rear end for added stability when trails get rough. In the past, we found the Siskiu more than capable for general trail riding, but when gradients steepened and terrain turned chundery, the rear end could feel unsettled – even a little wiggly when pushed hard.

The newly reinforced rear triangle, paired with a Fox Float DPS Performance shock and Fox 34 Float Rhythm fork, means the Siskiu now promises to be a solid all-round trail performer.

Keeping pace with modern trends, Polygon has also adjusted the geometry – steepening the seat tube angle to 77 degrees and slackening the head tube angle to 65 degrees. The result: greater efficiency on climbs and more confidence on descents.

A few nice-to-have extras on the Siskiu T8 include a tool mount, central triangle bottle cage mount, UDH compatibility, and a chunky chain protector. Our test bike in Eleon Green looked particularly sharp – shimmering purple in some lights and green in others – a great choice if you can’t decide between the two colours. For riders preferring a more understated option, the T8 is also available in light charcoal.

Overall, Polygon has clearly taken rider feedback on board with the new Siskiu range. The updates reflect what modern trail riders want – including cleaner cable routing for improved aesthetics. But all this value aside, the real question remains: how does the new Siskiu T8 actually perform on the trails?

On the Trail

Being well acquainted with the Polygon Siskiu T series, it didn’t take long to get reacquainted with the new models. The modern geometry is easy to feel at home on with minimal adjustment. Set your suspension, seat height and cockpit preferences and you’re ready to go. 

The Siskiu T8 is a well-balanced trail bike that perfectly toes the line for general trail riding. The Maxxis Dissector’s certainly add a bit of pep and reduced rolling resistance compared to the more aggressive treads previously specced on the Siskiu, and together with the reduced weight of the wheelset, allows the Siskiu to be – if not eager – then at least a compliant climber. After all, we all have to earn our turns at some stage. 

In addition to this, I would argue that the ride-ready geometry of the Siskiu is the perfect baby bear’s porridge for trail riding. While some cross country bikes can seem quite ungainly at low speeds, and other trail bikes can tend to wallow as reluctant climbers, the new Siskiu is capable for all day adventures, in comfort. 

The steeper seat tube angle perfectly centres you in the bike with enough weight over the front end for traction, while the cockpit setup with a 30mm rise, 9º backsweep bar and short 35mm stem meant maneuverability was never an issue on low speed technical climbing, with improved acceleration from the lighter wheelset and faster rolling tyre combination. It was only on very steep climbs that I felt the weight of the Siskiu T8, and found that the slacker 65º headtube angle wanted to wander.

For longer gravel or road commutes, the compression adjustment and two-position lever on the Fox Float Performance are also nice additions, effectively stiffening up the suspension for more efficiency on predictable terrain.

Despite the 29” only platform of this new generation of Siskiu T bikes (former generations offered 27.5” options for sizes small and medium only), the bike feels composed and retains a nimble yet surefooted nature when flicking around tight turns and popping off jumps and rocks.

Point it downhill and Polygon’s updates to the rear end are immediately noticeable. Where earlier Siskius could get unsettled in rock gardens or long stretches of chatter, the new T8 feels planted and confident – retaining composure when things get rowdy. The rear end has remained stiff through chunky trails throughout the testing period. 

This increased stiffness together with the Fox Float DPS Performance shock and Fox 34 Rhythm fork, means the new Siskiu T8 tracks smoothly without losing the playful pop that’s always made the Siskiu fun.

The slacker headtube angle definitely begs you to throw it down on steeper, rougher descents, but the Maxxis Dissector will find their limit as a front tyre quickly if you’re pushing hard on enduro or downhill descents. In a case of swings and roundabouts, our gripes of the weight of the former Siskiu must acknowledge that part of this weight – 2.6” Maxxis Assegai tyres – made the bike feel much more capable than its 135mm travel would suggest. If you are looking at more technical, chunky riding, swapping out that front tyre would be a first point of upgrade. 

Furthermore, while Polygon have done well to spec a full shimano drivetrain and brakes, we found the KMC chain to be an odd choice. While shifting was mostly problem-free, on the occasion we found slightly laggy shifting, the only culprit we could find was the KMC chain. 

If there’s one spec that feels out of step, it’s the dropper. The 150mm post (170mm on larger sizes) feels short by modern standards, and the plastic lever doesn’t match the otherwise solid spec list. It’s an easy upgrade, but one that would make a noticeable difference to the ride experience.

Overall, the new Siskiu T8 rides less like a budget-conscious compromise and more like a properly capable trail bike. It climbs willingly, descends well, and keeps its playful character intact – all while still landing at a price that undercuts most of its competition.

Our Take

Small gripes aside, for a newer rider or someone stepping up from their first entry-level bike, the Polygon Siskiu T8 is hard to beat. For under $4,000, it delivers a full Shimano 12 speed drivetrain, four-piston brakes, and Fox suspension – a far better package than my first proper mountain bike ever offered. And while you’ll pay significantly more for the same components on a premium-label frame, I’d argue that the Siskiu’s ride quality can still hold its own against some of the best in the trail segment.

As a self-confessed bike snob, there was a time when I wouldn’t have considered buying a brand like Polygon for myself. But after riding the new Siskiu T8, I can honestly say that if it were my only bike, I’d be a very content mountain biker. Fun, capable, and trail-ready, the Siskiu T8 once again proves its spot in the market as the “baby bear’s porridge” of trail bikes – not too much, not too little, but just right.

Brand Polygon
Model Siskiu T8
RRP $3799
Weight 14.9 (claimed weight)
From bikesonline.com.au
Available Sizes Small, medium (tested), large, extra large
Frame Material Alloy
Fork Fox 34 Float Rhythm
Shock Fox Float DPS Performance Series
Shifters Shimano SLX 12sp
Derailleur Shimano SLX 12sp
Crank Shimano Deore 32T
Chain KMC X-12
Cassette Shimano SLX, 10–51T
Hubs Shimano FH-MT400-B
Rims Polygon MT6 Alloy
Tyres Maxxis Dissector 29×2.40
Brakes Shimano BR-MT420, 4-Piston
Brake rotors Shimano SM-RT54, 180mm, Center Lock
Stem Polygon Expert, 35mm
Handlebars Polygon Expert, 780mm Width, 30mm Rise, 9° Backsweep
Seatpost X-Fusion Manic LC 150mm (S/M), 170mm (L/XL)
Saddle LINC Xtend