First Look: The New Polygon Siskiu T Ups the Ante for 2021
Indonesian bicycle manufacturer, Polygon, is ready to unleash its newest full suspension mountain bike for 2021; the redesigned and reengineered Siskiu T. Sitting smack-bang in the middle between the Siskiu D (Downcountry) and the Siskiu N (Enduro) the Siskiu T (Trail) is the brand’s most versatile do-it-all trail bike. And thanks to a whole suite of improvements to the frame, geometry and suspension design, the 2021 Polygon Siskiu T is about to get a whole lot more versatile.
With its bedazzling purple paint job, the Polygon Siskiu T8 is all-new for 2021, incorporating a whole bunch of improvements over the old model.
Same Face, New Muscles
You wouldn’t tell just by looking at it, but Polygon has actually gifted the Siskiu T an entirely new frame. The overall shape is very similar, and it’s still built around a single-pivot suspension platform with the seatstays directly driving the rear shock. A one-piece rocker link connects the seatstays to the frame, not only to help control the leverage rate, but also to provide lateral rigidity and decrease side-loading on the shock itself.
The alloy tubing is all-new however, and the geometry has received a hefty update too. There are also a number of key changes that have been brought over from the latest Siskiu D – a bike that we recently reviewed.
Taking on board recent geometry trends, the Siskiu T increases its reach by 25-30mm on each frame size.
Drink Some Water
For a start, you can now fit a water bottle inside the front triangle. How splendid! On all frame sizes, a 600ml water bottle will now sit inside a side-entry cage just underneath the rear shock.
Despite squeezing a bottle in there, Polygon has actually lowered the top tube to improve standover clearance. The seat tube has also gotten shorter, which allows for a longer travel dropper post to be fitted. The S/M sizes come with a 150mm popper, and the L/XL sizes come with a 170mm whopper.
In addition to the longer reach and slacker head tube angle, the Siskiu T also gets a shorter seat tube to accommodate a 150-170mm travel dropper post. And while the chainstays have gotten shorter, there’s still clearance for chubby 2.6in tyres.
Polygon has moved the shock up the downtube slightly, which has gifted the designers room to fit a 600ml water bottle just below it.
Fresh Geo & Wheelsize Options
Taking on board recent geometry trends, the Polygon Siskiu T gets a 1° slacker head tube angle, while reach measurements have grown by 25-30mm on each size – helping to push the front wheel out further for greater stability. To keep the whole wheelbase from getting too long though, the chainstays have shortened by 5mm. And finally, the seat tube angle has also steepened.
Polygon still produces the Siskiu T in two wheel sizes, and it’s a size-specific dealio. The 27.5in Siskiu T frame is available in Small and Medium sizes, while the 29in Siskiu T comes in Medium, Large and X-Large. That means for the lucky Goldilocks folk out there who fit a Medium, you’ve got both options at your disposal. For everyone else, the decision is a lot easier.
It Actually Has Less Travel
In a departure from every other new bike launch from the past year, the new Siskiu T actually has less rear suspension travel than the old model. Not by much, but we’re still happy that Polygon hasn’t succumbed to ballooning its trail bike into an enduro bike. As before, travel is also slightly different between the two wheelsize options;
- Siskiu T (27.5in): 150mm front & 140mm rear
- Siskiu T (29in): 140mm front & 135mm rear
Anti-squat has gone up by 10%, while overall progression in the leverage curve has been reduced ever-so-slightly.
Suspension kinematics have been tweaked, partially due to the rear shock having moved its mounting location a little further up the downtube. It’s also due to the main pivot having moved up too, which purportedly increases anti-squat by 10% over the old bike to improve pedalling efficiency.
To keep things smooth and compliant though, Polygon has moved to a lighter damper tune for the rear shock, and the overall leverage curve has been smoothed out, again to improve sensitivity. There’s also a touch less progression, giving riders more flexibility to tune the spring curve with volume spacers inside the rear shock.
Each frame size comes with 780mm wide hangers and a 35mm long stem.