Polygon SISKIU D5 Review
- Price: $989
- Frame: Aluminum
- Tires: 27.5 inches
- Gear: 2×9
What we like about it: The relaxed head tube angle, long reach, and steep seat angle make it versatile for any type of riding.
What we don’t like about it: The choice of frame sizes available is not complete enough and not good for riders who are too tall.
Rating: (4.8/5)
The Polygon SISKIU D5 features modern geometry with a slack head tube angle, long reach, and steep seat tube angle. These qualities provide incredible capabilities for riders seeking to tackle XC riding.
We will analyze the riding experience, key features, components, specifications, and other versions of the Polygon SISKIU D5. In the latter part of this article, we will also compare it with several top bike models. If you’re interested in more bike reviews, feel free to follow us.
Riding Experience
The Polygon SISKIU D5 boasts favorable geometry and carefully selected components. It has 120mm of front and rear travel. Among bikes in its class, it offers excellent value for the price.
To test the bike, I took the Polygon SISKIU D5 to Wayne National Forest in Ohio and booked a hotel nearby in advance using IHG. The forest features 145 miles of off-road trails, with narrow paths and surfaces covered in loose rocks and exposed tree roots.
Climbing
During uphill climbs, the SISKIU D5’s relatively upright seat tube angle and improved power transfer make it climb like a hardtail. I immediately noticed a solid power transfer with every pedal stroke, without any noticeable power loss.
On steeper ascents, I found the SHIMANO FC-MT210 36/22T TWO PIECE CRANK, 170MM crankset, paired with the SHIMANO drivetrain, particularly effective. Using a 22T chainring with a 36T freewheel allowed me to climb without exerting excessive effort.
Finally, the Polygon SISKIU D5 comes equipped with PERFORMANCE TIRE 27.5″x2.25″ wide-grain tires, providing good traction on various surfaces and preventing slippage.
Descending
The downhill capability of this bike are commendable. Its modern geometry design with a slack head tube angle and long reach ensures stability during descents.
The SUNTOUR XCM HLO front fork, combined with the SUNTOUR RAIDON LO AIR rear shock featuring 120mm of front and rear travel, allows for smooth riding on rocky terrain.
The quick rebound and compression damping minimize vibrations and impact, providing a more stable ride.
Additionally, the SISKIU D5 excels on narrow trails. Its tapered head tube design enables excellent front-end control during cornering. The 27.5×2.25 wheelset offers agile maneuverability on tight paths.
Finally, the SHIMANO MT200 hydraulic brakes with 180mm front and 160mm rear rotors deliver reliable braking power, allowing me to shorten my braking distance as much as possible during descents.
In summary, the Polygon SISKIU D5 is a full-suspension mountain bike that offers impressive all-around performance without exceeding its intended design strength. Furthermore, its price leaves me struggling to find any flaws.
Specification
The Polygon SISKIU D5 is available in three sizes (S-L) with internal cable routing, giving it a cleaner and more streamlined appearance. It also makes cleaning the bike more convenient.
Featuring a tapered head tube and 27.5-inch wheelset combination, the SISKIU D5 offers excellent front-end control and agile maneuverability on twisty trails.
The chain stay features chain protection stickers, reducing chain slap noise during aggressive downhill riding. Additionally, the mounting holes on the downtube support full-sized water bottle installation.
The top tube and seat tube have been reinforced to enhance the overall frame strength, instilling riders with greater confidence for intense rides.
Video
Other Versions
The Polygon SISKIU D5 is an outstanding all-suspension mountain bike with excellent overall performance. Its slack head tube angle, long reach, and steep seat tube angle allow it to handle a variety of terrains.
To cater to different preferences, we offer another full-suspension mountain bike with the same geometry aluminum frame under the same brand. This alternative version features larger 29-inch wheels and more advanced components, providing even greater riding capabilities.
Polygon SISKIU D7
The Polygon SISKIU D7 shares the same geometry and internal cable routing design as the Polygon SISKIU D5. It boasts a cleaner appearance and facilitates easier frame cleaning in daily maintenance.
In terms of components, the Polygon SISKIU D7 utilizes the ROCKSHOX RECON SILVER RL front fork with 120mm of travel and the ROCKSHOX DELUXE SELECT PLUS rear shock. As a result, the bike offers better vibration damping and support.
For the drivetrain, the Polygon SISKIU D7 features the SHIMANO FC-M5100 1×11-speed groupset. It provides a simple gear combination and a smooth shifting experience.
Lastly, the Polygon SISKIU D7 is available in frame sizes (M-XL) and is paired with 29-inch wheels, providing greater stability during descents. I particularly like its dropper post design, allowing for quick changes in riding position between climbing and descending.
Below, we will provide detailed specifications of the Polygon SISKIU D7 and list some other full-suspension mountain bikes from different brands with similar prices for your reference.
What do we like about it?
- Lower bend, tapered head tube design for excellent front-end control and increased durability.
- Internal cable routing throughout the entire bike for a cleaner appearance.
- Modern geometry with a slack head tube angle and longer reach for enhanced downhill stability.
- Responsive hydraulic disc brakes with reliable performance in all conditions.
- Excellent suspension support, allowing the SISKIU D platform to climb like a hardtail without sacrificing comfort.
- Quiet cable routing design to reduce noise during aggressive riding.
What don’t we like about it?
- Limited range of available frame sizes, not suitable for taller riders.
FAQ
- Can more travel be added to the rear shock of this bike?
Adding more travel can put additional stress on the frame and lead to premature wear, so we do not recommend doing so.
- What are the specifications of the rear shock on this bike?
SUNTOUR RAIDON LO AIR, E2E: 190x51MM.
- How to choose the right size?
Here we have a size chart for you. Of course, it doesn’t have to be according to this standard, and the best way to find the most suitable size is to try it out.
| Rider height | SIZE |
| 4’11” – 5’5″ | S |
| 5’3″ – 5’9″ | M |
| 5’7″ – 6’1″ | L |
Polygon SISKIU D5 Specs
Build
| Frame | aluminum BB Standard: BSA, 68mm, Threaded Color: Red – Black |
| Fork | SUNTOUR XCM HLO, 120MM TRAVEL |
| Rear Shock | SUNTOUR RAIDON LO AIR, E2E: 190x51MM |
| Bottom Bracket | BSA THREADED 68/73MM |
| Headset | THREADLESS ZERO STACK HEADSET, ZS 44/28.6 | ZS 56/30 |
| Stem | ENTITY SPORT ALLOY, E: 45MM, B: 31.8MM, R/D: 0DEGREE |
| Handlebar | ENTITY SPORT ALLOY, W: 760MM, BB: 31.8MM, R/D: 12MM, B: 0DEGREE |
| Saddle | ENTITY VOID SADDLE, ø 7mm |
| Seatpost | ENTITY SPORT ALLOY, DXL: 30.9x350MM |
| Pedals | PP FLAT PEDAL |
Groupset
| Rear Derailleur | SHIMANO RD-M3100 DIRECT ATTACH 9-SPEED |
| Front Derailleur | SHIMANO ALIVIO FD-M3120-E |
| Crank | SHIMANO FC-MT210 36/22T TWO PIECE CRANK, 170MM |
| Shifters | SHIMANO SL-M3100, 2×9-SPEED TRIGGER |
| Cassette | SHIMANO CS-HG200 11-36T 9-SPEED |
| Chain | KMC X9 |
| Chain Guide | none |
| Brakes | SHIMANO MT200 HYDRAULIC DISC BRAKE |
| Brake Levers | SHIMANO MT200 HYDRAULIC DISC BRAKE |
Wheels
| Rims | ALLOY DOUBLE WALL 584-15 32H FOR TYRE 584-35/68 |
| Spokes | Stainless Steel Spokes |
| Front Hub | F: ALLOY QRx100mm 32H CENTER LOCK / R: ALLOY BOOST QRx141mm 32H CENTER-LOCK |
| Rear Hub | F: ALLOY QRx100mm 32H CENTER LOCK / R: ALLOY BOOST QRx141mm 32H CENTER-LOCK |
| Tires | PERFORMANCE TIRE 27.5 “x2.25” |
| Disk Rotors | FRONT:180MM REAR:160MM CENTER-LOCK |
Comparison Table
| Bicycles | Click view | Travel | Frame material | Brake Type | Drivetrain |
| Polygon Xtrada 6 1×11 | Click View | 120mm front | Aluminum | Hydraulic Disc | 1 × 11 |
| Marin San Quentin 1 | Click View | 130mm front | Aluminum | Hydraulic Disc | 1 × 9 |
| Salsa Rangefinder Advent X 29 | Click View | 120mm front | Aluminum | Hydraulic Disc | 1 × 10 |
| Co-op DRT 1.2 | Click View | 120mm front | Aluminum | Hydraulic Disc | 2 × 9 |
Polygon SISKIU D5 vs Polygon Xtrada 6 1×11
When comparing these two bikes, I would highly recommend the former as it offers a better riding experience during descents.
In terms of suspension, the former has front and rear shocks with 120mm of travel, while the latter only has a 120mm travel front fork. This means the former can handle more intense downhill riding.
In the drivetrain department, the Xtrada 6 1×11 utilizes the Shimano Deore RD-M5120 drivetrain, which offers better drivetrain efficiency and smoother shifting compared to the Shimano Alivio and Shimano Acera series equipped on the SISKIU D5.
Both bikes use the same SHIMANO MT200 hydraulic brakes, indicating that they have similar braking capabilities.
Lastly, between these two full-suspension mountain bikes, the Polygon SISKIU D5’s full-suspension system can handle more challenging riding terrains, making it my top recommendation.
Polygon SISKIU D5 vs Marin San Quentin 1
Let’s take a look at the differences between these two bikes. The latter, with its hardtail frame, offers better climbing ability, while the former, with its full-suspension frame, provides greater stability during descents.
In terms of the drivetrain, the former bike features a mix of Shimano Alivio and Shimano Acera series components. Its 2×9-speed configuration offers more versatile speed options compared to the microSHIFT RD-M9195M on the latter bike.
When it comes to the braking system, the SISKIU D5 utilizes SHIMANO MT200 brakes, while the San Quentin 1 is equipped with Tektro M275 brakes. Both systems offer similar performance and reliability during rides.
Therefore, between these two bikes, I would highly recommend the full-suspension Polygon SISKIU D5, as it can handle more intense downhill riding.
Learn More: Is MARIN SAN QUENTIN 2 Worth Buying? [MARIN SAN QUENTIN 2 Review]
Polygon SISKIU D5 vs Salsa Rangefinder Advent X 29
These two mountain bikes feature the same SR Suntour XCM 120 suspension fork. However, the former also has 120mm of rear suspension travel, allowing it to tackle more challenging terrain.
In terms of the drivetrain, the SISKIU D5 utilizes a combination of Shimano Alivio and Shimano Acera series components, which are more reliable and trustworthy compared to the microSHIFT Advent X M6205 used on the Advent X 29.
As for the braking system, both bikes use SHIMANO MT200 brakes, offering similar braking performance and reliable functionality.
Ultimately, between these two mountain bikes, I prefer the full-suspension design of the SISKIU D5, as it enables me to take on more demanding trails.
Learn More: Is the Salsa Rangefinder Worth Buying? [Salsa Rangefinder Review]
Polygon SISKIU D5 VS Co-op DRT 1.2
Polygon SISKIU D5 and Co-op DRT 1.2 are both excellent mountain bikes, but they each have their advantages. The former excels in downhill riding, while the latter has stronger climbing capabilities.
In terms of suspension, the SISKIU D5’s 120mm front and rear travel offers superior downhill performance. On the other hand, the DRT 1.2’s hardtail frame and 120mm front suspension provide better power transfer during climbs, although the rear wheel can become too active during descents.
Moving on to the drivetrain, both bikes feature Shimano 2×9 speed systems, offering similar shifting experiences. As for the braking components, both bikes have excellent braking capabilities and rely on reliable brake systems.
In conclusion, if you enjoy downhill riding, the Polygon SISKIU D5 is more suitable for you. If you require stronger climbing capabilities, the Co-op DRT 1.2 is a better fit.
Summary
Above is my review of the Polygon SISKIU D5. In our opinion, this bike offers impressive overall performance in its price range and is suitable for entry-level riders seeking a full-suspension mountain bike. That’s why we gave it a rating of 4.8.
Of course, if you’re interested in learning about other full-suspension trail bikes, we also review a wide range of bikes in various price ranges, which can be equally interesting. Feel free to check out our other reviews.
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