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Polygon Siskiu D7 Review

An affordable entry-level full-suspension bike for taking your riding to the next level
Polygon Siskiu D7
Photo: Laura Casner
Best Buy Award
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Price:  $1,799 List
Pros:  Reasonable price, comes with a dropper post, fun on a range of terrain, efficient climber, playful on descents
Cons:  Non-boost fork, some cable rattle over rough terrain, can be overwhelmed on aggressive trails
Manufacturer:   Polygon
By Jeremy Benson ⋅ Senior Review Editor  ⋅  Oct 13, 2021
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80
OVERALL
SCORE


RANKED
#4 of 6
  • Fun Factor - 30% 8
  • Downhill - 35% 7
  • Climbing - 35% 9

Our Verdict

As the price of bikes continue to skyrocket, Polygon bucks that trend with their direct-to-consumer sales model and the affordable Siskiu D7. This short-travel bike has a sleek aluminum frame, 120mm of front and rear wheel travel, and a quality build for the price. Its versatile geometry excels on smooth to moderately rough intermediate descents with quick handling and a lively demeanor. A remarkably calm suspension platform gives it a zippy and efficient feel on the climbs and in rolling terrain. The build is budget-minded but functional with thoughtful component choices like wide handlebars and a dropper seatpost that help to enhance rider comfort and control. Whether you're just getting into the sport or upgrading to your first full-suspension bike, we feel this is one of the best values out there.

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Polygon Siskiu D7
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Polygon Siskiu D7
Awards Best Buy Award Editors' Choice Award Top Pick Award Top Pick Award  
Price $1,799 List$2,499 List$2,100 List$2,399 List$2,100 List
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Pros Reasonable price, comes with a dropper post, fun on a range of terrain, efficient climber, playful on descentsAwesome build for the price, versatile, well-rounded performanceEnergetic playful feel, lighter weight, 12-speed drivetrain, modern trail bike geometryHard charging on descents, long dropper post, modern trail bike geometrySupple rear suspension, versatile, fun on a wide range of terrain, affordable
Cons Non-boost fork, some cable rattle over rough terrain, can be overwhelmed on aggressive trailsFirm grips, saddle shapeFork needed immediate service, can be overwhelmed in more aggressive terrainHeavy, mediocre fork specification, not the fastest climbermoderately heavy, short dropper post, frame sizing runs a little small
Bottom Line An affordable entry-level full-suspension bike for taking your riding to the next levelA well-rounded mid-travel trail bike with a great build at an amazing priceA super fun, zippy, and affordable short travel 29erA ripping mid-travel 29er that is capable of charging hard downhillAn affordable mid-travel trail bike with a good all-around performance and a preference for the descents
Rating Categories Polygon Siskiu D7 Polygon Siskiu T8 Giant Trance 29 3 Kona Process 134 29 Trek Fuel EX 5
Fun Factor (30%)
8.0
9.0
9.0
9.0
8.0
Downhill (35%)
7.0
9.0
7.0
9.0
8.0
Climbing (35%)
9.0
8.0
9.0
7.0
7.0
Specs Polygon Siskiu D7 Polygon Siskiu T8 Giant Trance 29 3 Kona Process 134 29 Trek Fuel EX 5
Wheelsize 29 (27.5 on sizes S, M) 29 29 29 29
Rear Travel Length 120mm 135mm 115mm 134mm 130mm
Frame Material Aluminum Aluminum Aluminum Aluminum Aluminum
Measured Weight 33 lbs 32 lbs 8 oz 30 lbs 12 oz 34 lbs 13 oz 33 lbs 7 oz
Size Tested L L L L L
Available Sizes S, M, L, XL S(27.5), M(27.5 or 29), L(29), XL(29) S, M, L, XL S, M, L, XL XS, S, M, L, XL, XXL
Fork RockShox Recon RL, 120mm Fox Rhythm 34, 140mm Marzocchi Z2, 130mm RockShox Recon Motion Control Solo Air, 140mm RockShox Recon RL Solo Air, 140mm
Rear Shock RockShox Deluxe Select+ Fox Float DPS Performance EVOL Fox Float DPS Performance RockShox Deluxe Select RockShox Deluxe Select+
Wheelset Shimano hubs with Entity X15 doublewall disc rims Entity XL2 Disc Giant Tracker hubs with iant XCT tubeless rims, 25mm internal rim width Shimano hubs with WTB ST i30 TCS rims Formula front hub, Bontrager rear hub, Alex MD35 rims
Front Tire Schwalbe Nobby Nic 2.25" Schwalbe Han Dampf Addix Speedgrip EVO TLE 2.6" Maxxis Minion DHF EXO 2.3" Maxxis Minion DHF EXO 2.5" WT Bontrager XR4 Team Issue 2.6"
Rear Tire Schwalbe Nobby Nic 2.25" Schwalbe Han Dampf Addix Speedgrip EVO TLE 2.6" Maxxis Minion DHR II EXO 2.3" Maxxis Minion DHF EXO 2.3" Bontrager XR4 Team Issue 2.6"
Shifters Shimano Deore 11-speed Shimano SLX 12-speed SRAM SX 12-speed SRAM SX 12-speed Shimano Deore 10-speed
Rear Derailleur Shimano Deore 11-speed Shimano SLX 12-speed SRAM SX 12-speed SRAM SX 12-speed Shimano Deore 10-speed
Cranks Shimano Deore Shimano MT510 175mm(L-XL) SRAM SX Eagle DUB SRAM SX Eagle Race Face Ride 175mm
Chainring 32T 32T 30T 30T 30T
Bottom Bracket Shimano Deore BSA Threaded SRAM DUB Press fit SRAM DUB PF92 Shimano PressFit
Cassette Shimano Deore 11-speed Shimano SLX 12-speed 10-51T SRAM SX Eagle 11-50T SRAM SX Eagle 11-50T SunRace 10-speed 11-42T
Saddle Entity Void Entity XTENT Giant Contact (neutral) Kona Trail Bontrager Arvada
Seatpost Tranz-X 170mm (L-XL) 150mm (S-M) Tranz-X 170mm (L-XL) Giant Contact Switch TranzX Dropper Internal 170mm TranzX YSP18 Internal 130mm
Handlebar Entity Expert Alloy 780mm Entity Expert 780mm Giant Contact TR35 780mm Kona XC/BC 35 780mm Bontrager alloy 750mm
Stem Entity Expert 45mm Entity Expert 35mm Giant Contact SL 35 Kona XC/BC 35 Bontrager Rhythm Comp, 50mm
Brakes Shimano MT201 Hydraulic Disc Tektro HD-M745 4-piston Shimano MT400 Shimano Hydraulic Disc Shimano MT200
Warranty 5 Years on frame 10 Years on frame Lifetime limited warranty on frame Lifetime limited warranty on frame Lifetime limited warranty on frame

Our Analysis and Test Results

The Siskiu D7 is an entry-level full-suspension mountain bike that's...
The Siskiu D7 is an entry-level full-suspension mountain bike that's ready to hit the trails without breaking the bank.
Photo: Laura Casner

Should I Buy This Bike?


Whether you're just starting out or upgrading to your first full-suspension mountain bike, the reasonably priced Siskiu D7 is an excellent, affordable option to consider. With a slick-looking aluminum frame, modern trail riding geometry, and a quality build (for the price), this versatile bike is a blast to ride on a huge range of trails without breaking the bank. Distributed and sold direct to the consumer by bikesonline.com, Polygon bikes are known for their impressive value. The bike gets shipped straight to your doorstep with minimal assembly required (using the included tools) to get out on the trail. It isn't just the price that impressed us, however, as this short travel trail bike performs much better than we expected. The hydroformed ALX alloy frame has a killer paint job and a moderate trail riding geometry that not only looks the part but acts it too. With 120mm of rear-wheel travel paired with a 120mm fork, the Siskiu D7 excels on fast, flowy terrain and moderately rough intermediate-level trails alike. It feels quick, responsive, and playful and inspires the confidence to push your limits and improve your skills. On the uphills, the suspension platform is calm, and this bike is a zippy and efficient climber despite its moderate 33 lb weight. Additionally, it comes equipped with a quality, budget-friendly component specification, including a dropper post (a rarity at this price point), that is ready to rip straight out of the box. If you're operating on a budget but looking to get into the sport or upgrade from an old hardtail, check out the Siskiu D7.

This bike is a blast to ride on the right terrain. It feels quick...
This bike is a blast to ride on the right terrain. It feels quick and nimble with a playful demeanor.
Photo: Laura Casner

Fun Factor


Often, full-suspension bikes in the under $2,000 price range can be pretty underwhelming out on the trail. While it may not be some $5,000+ dollar superbike, in the context of affordability we found the Siskiu D7 to be a very fun bike to ride. It has a playful character and a relatively lively feel with responsive handling and a versatile trail riding geometry. Considering its shorter 120mm of travel, we found it to be the most fun to ride on smoother, flowier terrain and moderately rough trails that aren't too rough or steep.


BikesOnline.com makes it easy to get on the trail with a straightforward unboxing and assembly process and all the tools you need to put this bike together and start having fun. Its moderate modern geometry and 120mm of front and rear travel give the Siskiu D7 responsive handling and a distinctly lively and playful feel. We found it to be surprisingly versatile, performing well in nearly all situations on the climbs and descents. Thoughtful aspects of the build, like the well-appointed cockpit that includes a wide handlebar and a dropper seatpost, also help to enhance comfort, control, and confidence out on the trail. We feel this is a great entry-level bike for the rider seeking to progress their skills and have a good time doing it.

The Siskiu D7 excels on smooth, flowy trails and can handle...
The Siskiu D7 excels on smooth, flowy trails and can handle moderately chunky and rough terrain as well.
Photo: Laura Casner

Downhill Performance


The Siskiu D7 is a fun and lively descender that performs well on the descents when kept within its short travel limits. The moderate geometry helps to keep it nimble with responsive handling, while 120mm of front and rear travel smooth over moderately rough terrain while retaining an energetic and playful attitude. The price to build ratio is also quite high, with a quality component specification that comes together well when the rubber meets the dirt.


Polygon gave the Siskiu D7 a moderate (by today's standards) geometry that suits its 120mm travel length and lends itself well to cross country style trail riding on smooth to moderately rough terrain. The 67-degree head tube angle helps to keep the handling sharp, feels relatively composed at speed, and is confident in intermediate-level terrain. The 465mm reach on our size large test bike provides a reasonably roomy cockpit that avoids being too stretched out for a comfortable but not too aggressive descending position. A modest 1,189mm wheelbase and 436mm chainstays combine to keep this bike highly maneuverable and are one of the reasons it feels so nimble and easy to control. While its geometry isn't necessarily "progressive" or "long and slack", we feel it is appropriate for the Siskiu D7's travel length and intended purpose.

Moderate geometry and 120mm of travel combine to make the Siskiu D7...
Moderate geometry and 120mm of travel combine to make the Siskiu D7 responsive and highly maneuverable.
Photo: Laura Casner

With 120mm of front and rear wheel travel, the Siskiu D7 falls at the shorter end of the travel spectrum. Polygon employs a faux-bar suspension platform to control the rear wheel travel, which is a linkage-driven single pivot design. We found this design to provide relatively good small bump sensitivity, a supportive mid-stroke, and ample progression to avoid harsh bottom outs on larger impacts. Along with the shorter travel length, the mid-stroke support helps to give this bike its lively and relatively playful character, encouraging the rider to pump and pop their way down the trail. Considering it has only 120mm of travel, we found it performs best on flowy, smooth trails and even through some moderate doses of chunk. It does have its limits, however, and we definitely found them while testing. You can get down just about anything on this bike, but if you're interested in tackling steeper, rougher, more aggressive descents, we feel you'd be better off looking into bikes with more travel and a longer and slacker geometry.

Kicking up some dust while testing the Siskiu D7. This bike thrives...
Kicking up some dust while testing the Siskiu D7. This bike thrives when it's in its element, though it can be overwhelmed in super rough terrain.
Photo: Laura Casner

Considering the reasonable price of the Siskiu D7, it isn't dripping in the fanciest high-end components. Instead, it's clad with a budget-minded but functional build that we feel is pretty nice for the asking price and works well on the descents. The RockShox Recon RL fork works well enough and has a number of adjustments so that you can dial it in to your weight and preferences. The cockpit is well appointed with a 780mm handlebar and short stem providing ample steering leverage and responsive handling. A 170mm dropper seatpost (size Large and XL) is a great feature of this bike that helps get the saddle low and out of the way with a push of a lever for enhanced control on the descents. The wheels and tires can also be set up tubeless, which allows the rider to run lower tire pressures and enhance tire grip.

The Siskiu D7 is a surprisingly efficient and effective climber with...
The Siskiu D7 is a surprisingly efficient and effective climber with a calm pedal platform, responsive handling, and comfortable geometry.
Photo: Laura Casner

Climbing Performance


The Siskiu D7 is a surprisingly adept, capable, and efficient bike on the uphills. Its geometry is comfortable, handling is crisp and intuitive, and it has a very calm and supportive pedaling platform. At 33 lbs, it isn't the lightest bike out there, but we feel its weight is actually quite reasonable considering the price. Regardless, several PR's on climbs during testing confirmed our impressions of this short travel rig's solid climbing performance.


Weighing in at 33 lbs without pedals, our size large test bike doesn't necessarily qualify as being super lightweight. When you consider, however, that many carbon fiber trail bikes that cost three times as much (or more) than the Siskiu D7 weigh around 30 lbs, 33 lbs doesn't really seem that hefty. On the trail, that weight is barely noticeable as this bike feels far from sluggish. The 76-degree effective seat tube angle supports the rider nicely up above the bottom bracket and power transfer feels direct and efficient down into the pedals. The moderate length reach is roomy enough and the seated pedaling position is quite comfortable whether you're scrambling up a steep section or picking your way through a technical rock garden. Handling is quick and the Siskiu is highly maneuverable thanks to the combination of its shorter wheelbase and 67-degree head tube angle.

The Siskiu D7 feels great while climbing whether on smooth trails or...
The Siskiu D7 feels great while climbing whether on smooth trails or scrambling up technical sections.
Photo: Laura Casner

One thing that really stood out about the Siskiu D7 was just how calm the rear suspension felt when pedaling. According to their website, they've revised the kinematics for a higher level of anti-squat which sounds about right based on our experience. While seated, there was virtually no noticeable pedal bob or wasted energy through suspension movement. Out of the saddle, there was a tiny bit of pedal-induced bobbing, but it was minimal compared to some other bikes we've tested. That said, it still seemed to react well to small bumps and maintain solid climbing traction in most conditions and situations. Additionally, the Rock Shox Deluxe Select+ rear shock has a compression damping switch and the fork has a compression dial that can be used for a more locked-out feel for extended climbs on paved or dirt roads.

The Siskiu D7's climbing efficiency makes it a little easier to earn...
The Siskiu D7's climbing efficiency makes it a little easier to earn those descents.
Photo: Laura Casner

While budget-conscious, Polygon thoughtfully chose the components on the Siskiu D7 for their quality and functionality. The Shimano Deore 11-speed drivetrain is a great example. This setup has crisp shifting and all the range of 12-speed drivetrains, just in a more cost-effective 11-speed package. The 2.25-inch wide Schwalbe Nobby Nic tires are a bit narrow for our taste, but they are relatively fast-rolling while still providing good pedaling traction in a wide range of conditions. Again, the cockpit setup lends itself to precise steering and the Entity Void saddle proved to be quite comfortable with just the right amount of padding and an agreeable shape.

The ALX alloy frame has nice lines a fancy-looking paint job.
The ALX alloy frame has nice lines a fancy-looking paint job.
Photo: Laura Casner

Build


The Siskiu D7 is built around a slick-looking ALX Alloy frame with a looks-more-expensive-than-it-is paint job. The frame has 120mm of rear faux-bar suspension paired with a 120mm travel fork. Small frame sizes come with 27.5-inch wheels only, Medium can be ordered in 27.5-inch or 29-inch, and Large and XL frames are available with 29-inch wheels only (Be sure to check Polygon's sizing and geometry chart to find the right size for your height). The frame has front and rear thru-axles, molded chainstay protection, internal cable routing, and one bottle cage mount on the downtube. While the components on the Siskiu D7 are far from flashy, trust us when we say that the build is quite nice for the price.

The RockShox Recon RL fork handles the front suspension duties with...
The RockShox Recon RL fork handles the front suspension duties with a RockShox Deluxe Select+ in the rear.
Photo: Laura Casner

Polygon has equipped the Siskiu D7 with a RockShox suspension package to control the 120mm of front and rear-wheel travel. A RockShox Deluxe Select+ handles the rear suspension and features a rebound adjustment and 2-position compression damping/climbing switch. The fork is a RockShox Recon Silver RL with an adjustable air spring and external rebound and compression adjustments. The Recon is far from our favorite fork and we're a little disappointed that it doesn't have a Boost front axle, but at this price point, it's hard to complain too much.

The 11-speed Shimano Deore drivetrain has plenty of range and simply...
The 11-speed Shimano Deore drivetrain has plenty of range and simply works well.
Photo: Laura Casner

We think Polygon made a great choice with the 11-speed Shimano Deore drivetrain on the Siskiu D7. It may lack the "cool factor" of a 12-speed drivetrain, but it works very well, has plenty of range, and helps to keep the price of the bike down without sacrificing performance. It also features a threaded bottom bracket and durable Shimano Deore alloy cranks. Shimano MT201 hydraulic disc brakes perform the slowing and stopping duties. They aren't the most powerful brakes around, but they are reliable and work well once you get used to their feel.

Schwalbe Nobby Nic tires are a versatile option that work well in a...
Schwalbe Nobby Nic tires are a versatile option that work well in a range of conditions.
Photo: Laura Casner

The Siskiu D7 rolls on a set of Entity X15 rims laced to Shimano hubs. These rims are tubeless-ready and come pre-taped, you'll just need to purchase from tubeless valve stems and sealant to finish setting them up tubeless. This is a relatively inexpensive upgrade that we feel is well worth it. The Schwalbe Nobby Nic are versatile and relatively fast-rolling tires that perform well on a wide range of surfaces, and the Performance version can be set up tubeless. We feel you could easily enhance the overall performance and ride feel of this bike by upgrading to a higher volume tubeless tire setup.

A nice wide handlebar and short stem provide for responsive handling...
A nice wide handlebar and short stem provide for responsive handling while the dropper post lets you change saddle height on the fly.
Photo: Laura Casner

The cockpit consists mostly of Entity, Polygon's house brand, components. We feel they did a great job creating a comfortable and responsive front end with a nice, modern width 780mm alloy handlebar and a short 45mm alloy stem. An Entity Void saddle proved to quite comfortable with a medium level of cushioning and a crowd-pleasing shape. One of the highlights of the build is the Tranz-X dropper seatpost that allows you to raise and lower your saddle with the press of a lever. Size large and XL frames come with a 170mm travel dropper, while small and medium sizes come with a 150mm post. Bikes in this price range often come with rigid seatposts, so it is refreshing to see a dropper on the Siskiu D7.

With a nice alloy frame and a reliable component specification, we...
With a nice alloy frame and a reliable component specification, we think the Siskiu D7 is one of the best values out there.
Photo: Laura Casner

Value


There's no question that mountain bikes are expensive, so it's refreshing to see Polygon doing their best to produce affordable models, like the Siskiu D7, to make the sport more accessible for new riders or those looking to upgrade to their first full-suspension bike. This bike comes ready for action with a versatile and comfortable geometry and solid price to build ratio. If you're already a hardcore or seasoned rider, you'll probably want to explore some other (more expensive) options, but if you're new to the sport or still learning the ropes, we feel this is one of the best values that you'll find.

Conclusion


With the Siskiu D7, Polygon has managed to create a versatile short travel trail bike at a very reasonable price. Polygon's direct-to-consumer sales model helps to keep the price low while still providing a quality frame and reliable components. The price to performance ratio is also quite high, and this bike is an efficient climber and a quick and playful descender. The cost of modern mountain bikes is a significant barrier to entry for many riders but the Siskiu D7 proves that you don't have to completely break the bank to get into the sport or upgrade to a full-suspension bike.

If you're considering jumping into the sport of mountain biking, the...
If you're considering jumping into the sport of mountain biking, the Siskiu D7 is an affordable option to get you out on the trail.
Photo: Laura Casner

Other Versions


Polygon makes two additional, more affordable, models in their Siskiu D line that share the same geometry as the D7 we tested.

The Siskiu D6 comes with an SR Suntour XCR 32 fork, an X-Fusion O2 Pro RL rear shock, a 10-speed Shimano Deore drivetrain, and an X-Fusion dropper seatpost. It retails for a very reasonable $1,499.

The Siskiu D5 is the base model with a staggeringly low price of $1,199. It comes with an SR Suntour XCM HLO fork, SR Suntour Raidon LO rear shock, 2 x 9-speed Shimano Alivio drivetrain, but does not come with a dropper seatpost.

Jeremy Benson