2021 Polygon Siskiu T8 – Long Term Review
On paper there isn’t much to complain about with the Siskiu T8, the geometry is dialed, it’s got the right amount of travel for a ‘do it all bike’ and the value is spot on too. This is one of those rare situations when a bike lives up to those expectations. It’s everything a trail bike should be. It’s fun and can be ridden on a wide variety of terrain and is more than capable enough on the descents.
After taking the time to get the setup dialed it’s safe to say for my riding this is my ideal bike, even better that it’s one of the best value bikes on the market and apart from a few spec tweaks mainly to the finishing kit, it’s spot on. To me, this is the point of diminishing returns, and after riding more expensive bikes in the past, I have had to question, that for my level of riding is it worth spending any more? It’s safe to say the answer is no.
If you aren’t familiar with the Polygon Siskiu Range: you have the Siskiu D for Down Country, which I reviewed last year, Siskiu T for Trail, and Siskiu N for Enduro. The Siskiu T came out in 2017 to some fan fair as it was a capable ‘do it all trail bike’ at a great price, but bikes have changed a lot since 2017 and the new 2021 model is bang up-to-date with all those trends.
The Siskiu T8 in all its glory
Frame and Geometry
The most welcome change for 2021 is that the frame now accommodates a water bottle in the front triangle!
The T8 I have reviewed is the top of the line model and coming in at $3499 AUD and $2399 USD. There is also the T7 available, which is $2699 AUD and 1899 USD and comes with more affordable specs, which would be a great option if you plan to progress and upgrade the fork later on.
The bike also comes with wheel-specific sizes, so SM and MD sizes have 27.5in wheels, and MD through to XL are available in 29in wheels. Travel for 29in bikes is 135mm in the rear and 140 up front and for 27.5in bikes, they have 140 in the rear and 150 up front. The frame is also made of alloy.
The geometry is bang up to date with all the trends
But my favorite thing about the bike is the geometry and I’ve found it bang on for a ‘do it all bike’. At 185cm the size LG fits me perfectly, which has a 480mm reach, up 30mm from the old model.
The effective seat angle is also nice and steep at 76.5° but I’ve measured it to be slightly steeper. This may feel a bit different coming from a setup with more old school geometry and might feel like the bars are a little closer seated, but stand up and you are welcomed with a lot more room, which is great on the descents.
The head angle is slack but balanced for the style of riding at 65.5° on the 29er and 65° on the 27.5. The chainstays are nice and short too at 430mm on the 29er’s and even shorter at 425mm on the 27.5.
The paint job ain’t to shabby either
To round it all off, the seat tubes are super short, so it’s good to see a 150mm dropper on SM and MD frames and 170mm drop on LG and XL frames. The standover is also super low making the bike easy to maneuver and in combination with the low BB, makes you feel ‘in the bike’ rather than ‘on top of it’, which also makes cornering great too.
Overall there is nothing I would change here. The geometry for this style of bike is dialed. It’s great to see this kind of geometry at this price as at the end of the day, it doesn’t cost you any extra to design a bike with decent geometry.
The suspension design is pretty simple being a linkage actuated single pivot. I’ve been riding a lot of single pivots lately and don’t understand why they get so much flack. I’ve been very impressed with the Marin Alpine Trail and the Siskiu T. They might have slightly higher anti-rise, so not as active under braking, but this has never really hindered me. It also means that the suspension preserves the geometry of the bike very well under brakes, which is great on steep trails, so it’s personal preference on what you prefer.
The one piece linkage also helps to stiffen the linkage while minimizing weight.
For 2021, the kinematics were slightly changed. This was mainly due to Polygon making room for the water bottle but it brought about some welcome changes. Anti-squat was increased around 10%, which was noticed on the climbs, as the pedaling platform is noticeably firmer out of the saddle. This also led to the axle path staying rearward for longer. Did I notice this? Maybe a little but I think it was a combination of factors that led to the improved suspension performance over the last model, which did feel a little harsh. I think that the custom-tuned shock with a light compression tune and reduced overall progression made the biggest difference. But it is good to know that it is still progressive enough to run coil, which Polygon team rider Dan Wolfe is running. The reduced progression also allows a bit more room to tune with volume spacers, which is exactly what I did.
So in the rear of the bike, I went from the .4 spacer to the .8 but I would check the unique shock code ID on your shock on the Fox website as some of the bikes do come with a .6 from the factory. With the stock .4 spacer, I was running around 175 psi, which was 30% sag and it felt a little harsh and I had too much feedback through the pedals. So I went up to the .8 with 160-165 psi and it was perfect. Super supple off the top, nice and smooth over the chunk, there was plenty of support to push against and more than enough ramp-up at the end of the stroke, cliche but dialed. I weigh around 83kg kitted and this was around 30% sag, so if you weigh more or less you may need to adjust what spacer you use. In terms of rebound, I ran 4 or 5 clicks of rebound from fully clockwise and the compression wide open, I never felt the need for the trail or lockout modes.
The .8 spacer is the go for my 83kg weight
Upfront it took a bit of tweaking with the spacers too. The bike comes stock with 0 spacers and it blew right through its travel. The fork really needs 3 or 4 spacers to make it sing. After that, I was pretty much running the recommended settings at 83psi and 6 clicks of rebound from fully clockwise. For the compression, I had it one-third turned from fully open, as the fork did have a bit of a tendency to dive a little, so this just added a bit more control and helped it sit up a bit more in the travel.
You would be hard-pressed to find a better spec’d bike for the money. But there are a couple of tweaks I have made. So let’s start with everything I like. The first thing is that the money has been spent where you want it and that’s in the suspension. Once I got the setup dialed I was very impressed with the suspension. The Fox 34 Rhythm upfront is a bit stiffer than Fox’s other 34mm forks, which was noticeable on the trail. I like the fact a heavier more enduro-focused fork wasn’t used as the 34 suits the intentions of the bike better. The fork feels great too, it does feel a little harsh at times and does dive a little, but getting the setup dialed reduces this to a degree. The Fox DPS shock was also faultless and again suits the intentions of the bike and is super easy to set up.
The Shimano SLX 12-speed drivetrain is a personal favorite of mine too, the 10-51t cassette offers great range at a decent weight. The shifting is clean and crisp and more forgiving on rougher changes. The Tranz X dropper is a great value option too, coming in at 170mm drop on my size LG. It’s great to see a proper length dropper spec’d at this price point but I would consider upgrading the lever to something nicer in the future.
Onto the wheels and tires now and the 2.6in Schwalbe Hans Dampf are a great tire for this bike. Even though I only ran them for a short period, I love this thread pattern, they are fast and provide consistent levels of grip. If you bought this bike I would keep the front as a spare for the rear and get the soft compound version upfront for a dialed setup, but in saying that, the speed grip compound provided surprisingly good traction. The wheels also did the job well, at this price a better wheelset is asking a lot. They come tubeless taped from the factory, which is awesome, so if you want to go tubeless all you need is valves and sealant. The main downside is they are heavy at around 2.5kg, so if you want to reduce the unsprung mass of the bike and speed up the acceleration, this would be your best upgrade.
So let’s talk about the brakes and the 4 piston Tektro Orion brakes I’ve had on my past 2 bikes. The brakes do the job well once they have good pads and rotors. It would have been nice to see some better rotors compared to the resin-only option from the factory. So if you find you are lacking some power, a set of rotors that aren’t resin only and a pair of Shimano Saint metallic pads (the non-finned version), will have you stopping with ease.
So now onto the finishing kit, which I have mostly swapped out. First off the grips, and these have since been changed from the factory so most of my comments here are now void. But you will be stoked to know that the new grips are really grippy and come with a nice half-waffle design. The saddle I didn’t get along with either, It wasn’t that it was uncomfortable, it was that the shape of the saddle and rubber under the saddle had a nasty habit of grabbing your shorts on rock rolls, leading to some awkward situations, so I swapped it out pretty quickly. Lastly, the stem and bars, and this was a more personal preference. The bars and stem are a great width and length, just for the slightly lower stack height of the bike, I prefer a higher-rise as well as a bit more back sweep, as the stock ones felt a bit too straight for my liking.
So overall, as you can tell, I really was impressed with the spec of the bike.
I enjoyed climbing the T8. Its pedals are much better than the 15kg weight might indicate. The climbing position is great too, the steep seat angle gets you right over the cranks on steeper inclines. The pedaling platform is decently firm too, thanks to the higher anti-squat. Out of the saddle, there is only a little bit of bob but I was pleasantly surprised that on sprints not a lot of energy was wasted through the suspension. The 620mm stack also makes it easy to weight the front end of the climbs.
One thing to note however is that the BB is quite low, so with the 175mm cranks on the size LG I did have a few pedal strikes, for those who get frustrated by pedal strikes some shorter cranks might be worth a look.
There is also some flexibility to lighten the bike. If you went tubeless with some fast-rolling tires and a lighter wheelset, you cut 700-800g of rotational weight off the bike, which would make it a bit more rapid on the climbs and accelerate a fair bit better too.
Now onto descending and this is where the fun is at. It is the definition of a modern trail bike. I’m a huge fan of picking a bike for 90-95% of your riding. I’m not doing too much XC, I’m mostly riding trails and enduro trails but I’m not hitting drops over 2m and attacking rough technical features and that’s where this bike fits in perfectly. Overbiking has been very popular in the past few years and I think this is the type of bike most of us only need. The 65.5° head angle with the roomy 480mm reach on the size LG provides more than enough stability on fast trails and keep you out of trouble on steep pitches. On fast trails, I’ve been on trail bikes in the past where I was wishing for more stability but I was more than comfortable on the T8. I think this is the golden zone, any longer, and slacker and I think you would start to detract from the versatility of the bike.
Great for the odd bike park lap too!
The suspension also helps the bike stay composed on these trails. It’s supple once you get the setup dialed and there’s plenty of support to push against and bottom-out resistance on bigger drops, it’s only once there are repeated fast big hits that you find on rougher enduro and downhill trails that the bike starts to become overwhelmed. However, this is to be expected as it is a 135mm travel trail bike.
I can see a lot of people wanting to make it more aggressive but I think the more trail-friendly factory setup is the bike’s best form. It’s not a bruiser of a bike like the Norco Sight or Commencal Meta TR, it’s a lot more versatile and for Australian trails, I think it’s best kept this way, given our trail centers aren’t the most difficult and rough and don’t have a lot of elevation to play with, so a bike that’s easy to maneuver and efficient will serve you better.
At the end of the day, a trail bike is meant to be fun and the T8 has it in spades. I’ve been known to be a pretty boring rider, just getting through the trail, not trying to pop off any extra features for some bonus points. But in the past 6 months on the bike I’ve been encouraged to manual off everything and hit doubles I didn’t even know existed. I have ridden bikes with short 430mm chainstays before, but there’s something different encouraging me here. So 10/10 on the fun factor there.
The Siskiu T loves a good double
Balance was also a concern when I was looking at the T8 on paper, with modern longer-reach bikes, there is a need to weight the front end more in corners, especially when the chainstays are shorter. On the T8 this wasn’t too much of an issue at all, yes, you need to weight the front end a little more on corners but not as much as you would expect. The bike absolutely rails corners, which is a polygon specialty thanks to its low BB. When it comes to my ideal bike for my riding, this is my quiver killer. It’s got more than enough travel and stability to get me out of trouble on most descents and more importantly it’s fun, and that’s why I ride!
Onto the durability of the bike and there’s not too much note here, the frame has been solid, there’s no premature wear or play in the bearings or bushings on the seat stay. I did have to grease the headset from the factory, as it was a little creaky but that is a 5-minute job. Other than that I have only slightly dented the rear rim, this is more of a cosmetic issue. A few spokes needed tightening after a few months but I would put this down to regular maintenance, so if you get the bike I would check this every now and then. Everything else has been great.
When it comes to trail bikes there’s a broad spectrum of bikes on offer. Some bikes like the Commencal Meta TR, Norco Sight, and Vitus Escarpe border on enduro bikes, so if you are looking for something really aggressive, then I would look more towards them. However, the Siskiu T stacks up well against bikes like the YT Jeffsy, Marin Rift Zone, Giant Trance X, Orbea Occam, and Nukeproof Reactor all of which I’ve compared in my buyer’s guide.
Compared to other bikes I’ve reviewed such as the Merida One-Twenty and the Norco Fluid I would say the Siskiu T is a better all-around bike. If you prefer something a bit quicker on the XC stuff and want a great value bike, the Merida is a great option as the spec for the money is tough to beat, but on the descents, the Siskiu T is in a different league and a lot more capable. Compared to the Fluid, I would say the Siskiu T is a better bike all around in my opinion, even on the climbs. It’s still a great value bike, the Siskiu T is just that bit better in all aspects and didn’t have me asking as many questions.
- Value: The whole package from spec, ride, and geometry is dialed for the money.
- Geometry: It’s what a modern trail bike should be, it strikes the balance between fun and stability, and the climbing position is perfect too.
- Versatility: I have ridden everything from XC to enduro trails and never thought that ‘oh, I wish I had this or that kind of bike’, only at the extreme ends of XC and enduro.
- Finishing Kit: I wasn’t a huge fan of the saddle and handlebars
- Brake Rotors: It would be nice to have some more premium rotors that can work with both resin and metallic pads.
- Dry Headset: It would be nice if the headset had a little more grease from the factory as a lot of people getting this bike might be less confident on tools even if it is a simple job.
Read the original article here.