Polygon Siskiu T8 Review
Cons: Came with wrong size dropper post, moderately heavy
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Our Analysis and Test Results
Should I Buy This Bike?
The Siskiu T8 has a great all-around performance and was a close runner up for our Editor's Choice Award. This mid-travel trail bike is comfortable and downright fun to ride up, down, and all around. It doesn't particularly excel at any specific thing, it's just good at everything. The more we rode the Siskiu, the more we grew to like it and it quickly became a tester favorite for its consistent and well-rounded performance that responds well to rider input and doesn't hold you back from getting after it. The geometry is modern, but far from extreme, and the 140mm of front and rear wheel suspension feels balanced and performs better than most bikes in this price range. High speeds or low speeds, mellow or gnarly, we didn't find a situation where the Siskiu felt out of place. This is one of only two bikes in this review that our testers felt truly comfortable riding as hard as they could, a huge compliment for such an affordable bike.
When asked what he thought about the Siskiu, one of our testers said, "I couldn't wipe the smile off my face". It's true, we all saw it, he was grinning ear to ear while riding this bike. Our testers love riding bikes, but this isn't the typical response when testing the bikes in this price range. Feeling 100% confident in a bike and its components really allows you to focus on riding and not thinking about the bike keeping up with your intentions.
The well-rounded performance of the Siskiu T8 is one of the main reasons this bike is so fun to ride. Whether you're just cruising or trying to beat your own time on a descent, the Siskiu feels composed and ready for whatever comes your way. The quality component spec doesn't hurt and certainly helps this bike feel more shred ready than most of the other bikes in this review. It's not the most playful bike on descents, nor does it feel completely glued to the ground, it strikes a nice balance where it likes the occasional side hit and really wants to just rally down your intended line.
When the dust settled, we rated the Siskiu at the top of the pack along with the YT Jeffsy for its consistently entertaining ride. The Jeffsy is just as well rounded but has a slightly higher propensity for getting off the ground.
For most riders, their primary reason for riding is ripping the descents. The Siskiu T8 is no slouch on the downhill and can hold its own far better than most people would expect for a sub-$2500 bike. If our testers stoke levels were any indication, this bike inspired the confidence to charge on the descents with a balanced feel that worked well at all speeds and trail types and never made us feel the need to hold back.
A bike's geometry is one of the biggest factors that influences its downhill abilities and Polygon nailed it with the Siskiu. They gave it a modern numbers without going to extremes with the length of the wheelbase or reach which helps to explain why it performs so well all-around. The measured head tube angle of 66.25-degrees hits a good sweet spot that is slack enough to charge into rock gardens or steeper trails while not being too slack resulting in sluggish handling. The 1194mm wheelbase is moderately long, not so long that it loses playfulness or struggles at lower speeds or in corners, but long enough that when combined with the 438mm chainstays give it excellent stability at speed. Our testers agreed that the geometry felt dialed and there wasn't anywhere this bike didn't perform well on descents as a result.
The Siskiu's build is one of the most impressive in this review, another factor that really works in its favor on descents. The suspension is slightly higher-end than all of the competitors, other than the YT Jeffsy, and it feels balanced, relatively plush, and sturdy. The RockShox Revelation fork has larger stanchions and a stiffer chassis than forks like the Recon found on other models and flexes less under braking and steering, plus it is more tuneable. The rear suspension design and shock feel solid, supportive in the mid-stroke with a progressive ramp up to the end of its travel. This suspension generally worked very well, though we found it to be a little harsh in high-frequency chop, adjusting the air volume spacers could likely fix this issue.
The cockpit setup is dialed straight from the box and we didn't feel the need to make any changes. We were dismayed by the shorter than advertised dropper seat post that came on our test model, but that didn't take away from this bike's downhill prowess. Schwalbe Nobby Nic tires haven't been our favorite in the past, but we were surprised to love the way they performed on this bike. The width of the rims seemed to pair especially well with the tire width and gave them a nice square profile that maintained excellent cornering traction and exceeded our expectations.
The Siskiu complements its stellar downhill abilities with a solid climbing performance. It's not a featherweight XC bike by any means, and at 31lbs 8oz its right up there with the heavier models in this review. It really doesn't feel all that heavy, actually, it felt like one of the fastest rolling and easiest climbers of the bunch.
It has a somewhat middle of the road geometry that puts the rider in a comfortable seated pedaling position. The 74.5-degree seat tube angle feels appropriately steep and puts you almost right above the cranks for solid power transfer. The reach is moderate at 448mm so you don't feel too stretched out or too cramped, and steering input feels very direct and not prone to wandering. The 1194mm wheelbase is a nice length that never feels too long and is quite capable in low speed technical and tight terrain.
The rear suspension is relatively active, especially at the very top of the stroke. While seated and pedaling it didn't result in too much bobbing, although more than the YT, when out of the saddle the suspension movement was more noticeable. The three position compression damping switch helps to reduce pedal bob and we found the middle, "trail", setting to feel somewhat more efficient for extended periods of climbing.
The Siskiu T8 just barely squeaks into our under $2500 review and is the most expensive model in this test with a quality component specification to match. This bike comes ready for action and you won't need to upgrade or change anything about it before heading out to ride. In this price range, a few hundred dollars goes a long way when it comes to components and the differences in performance can be quite dramatic. This is the case with the Siskiu and the YT Jeffsy Base 29, both of which have superior builds and performance compared to the other models in this review. One interesting thing about the Siskiu is that it comes with either 27.5" or 29" wheels depending on the frame size. Small and medium frames are offered in 27.5", and medium, large, and XL frames are available in 29".
The 29" wheeled Siskiu we tested has 140mm of front and rear wheel travel. Polygon has spec'd a nice-for-the-price RockShox Revelation RC fork up front. The Revelation is beefy and stout feeling, especially when compared to some of the flimsier forks found on bikes in this price range. A RockShox Deluxe RT3 Debonair shock handles the rear suspension and is highly tuneable with an adjustable air spring, rebound adjustment, and a 3-position compression damping switch. This setup feels nice and balanced front and rear.
The Sisikiu has a handful of their house branded Entity components attached to it and this includes the Entity XL2 wheelset. These tubeless compatible wheels have a nice modern 30mm internal rim width and feel relatively damp and burly. They've spec'd a matching set of Schwalbe Nobby Nic tires in a 2.35" width. When paired with the wide rims, the Nobby Nic's have a somewhat squared off profile and provided heaps of traction when climbing, braking, and cornering.
The cockpit setup also consists of numerous Entity components. They've put a nice modern 780mm wide handlebar and a short stout 45mm stem on the front of the bike. This combo is comfortable and provides responsive handling. The Entity saddle was more comfortable than we expected with a good width and medium density padding. The saddle sits atop an unbranded dropper seat post that is supposed to have 150mm of travel. For some unknown reason, our test bike came with a 125mm travel seat post, and out testers found themselves extending it beyond the minimum insertion line to fit on the bike, not ideal. The dropper itself worked well and we liked the under-mount 1x remote lever that it comes with.
A Shimano SLX/XT drivetrain is a nice touch. The 11-speed drivetrain shifts crisply and precisely and we found the 11-46 tooth cassette and 32-tooth front chainring to offer adequate gear range for virtually all situations. The Shimano BR-MT500 brakes are nothing fancy, but we found them to work very well on this bike and provide good stopping power.
With a retail price of $2,499, the Siskiu just makes the price cutoff and is the most expensive model in our under $2500 review. Despite being slightly more expensive than the competition we do still feel that this represents a good value considering this is one of our highest rated models with a great all-around performance and a quality build for the price.
It was a tough battle for the top step of the podium in our under $2500 mountain bike review. In the end, the Siskiu T8 was just narrowly edged out by the YT Jeffsy but it remains one of our most highly regarded bikes in this price range. The Siskiu performs well on both the climbs and the descents, at any speed, and in any type of terrain. This bike is far more capable than you'd expect, with a build and confidence-inspiring trail manners that exceed the asking price. If you're looking for an affordable trail bike that can do it all well we don't think you could go wrong with the Siskiu T8.
Polygon makes the Siskiu T8 in both 27.5" and 29" wheel sizes depending on the frame size. Small and Medium frames are offered with 27.5" wheels and come with a 150mm travel fork. Medium, Large, and Extra Large frames are available with 29" wheels as tested.
-The Siskiu T7, $1,899, has the same geometry as the T8 model we tested but comes with a RockShox Recon fork, X-Fusion 02 Pro rear shock, a 10-speed Shimano XT drivetrain, and Shimano BR-MT365 brakes.
-The Siskiu N8, $2,699, is a more enduro style machine that has 160mm of rear and 170mm of front wheel travel, slacker geometry, a SRAM NX Eagle drivetrain, and beefy Schwalbe Magic Mary tires.
-The Siskiu N9, $2,999, has the same geometry and travel as the N8, with beefier Fox suspension, a SRAM GX Eagle drivetrain, TRP Slate T4 brakes, and Schwalbe Magic Mary tires.
— Jeremy Benson, Kyle Smaine