2017 Polygon Siskiu D8.0 Dual Suspension Mountain Bike

Or 6 x $333.17 Per Month
Global RRP: $2,499.00
(You Save $500.00)


The Polygon Siskiu D8 received consistent, positive feedback from the industry last year. Flow Mountain Bike's review noted the D8 had "such solid performance and reliability from the components fitted to a sturdy and well-thought out frame". Mountain Bike Australia Magazine also reviewed the D8 and said the bike has "amazing spec for the dollars" which have been built around a frame that was "stiff and respectively light".

This Siskiu D8 for this year, like the D6 and D7 models that precede it, also features Polygon’s proprietary 2THRU system. This system allows the rear axle to use either a 9mm quick release skewer, as supplied, or a 12mm thru axle. This future-proofs the bike should you decide to upgrade your wheels in future.  Whichever axle you choose the design results in a much stiffer rear end with more predictable handling and better cornering. 

 A thru axle is also included on the upgraded Rockshox Recon Gold Air suspension fork. The Recon Gold fork features alloy stanchions to further reduce the weight at the front end of the bike. One of the most popular features on the entire bike is the remote lock out lever sitting on the handlebars, so you won’t need to remove your hands from the bars to operate the lock out.

A Rockshox Monarch RT rear shock, complete the Rockshox damping duties. These feature the Rockshox Solo Air technology and an advanced lock out lever combined with rebound adjustment – perfect for almost all trail conditions

The drivetrain on the Siskiu D8 comes equipped with an upgraded 22 speed Shimano setup combining SLX front derailleur and shifters, together with the latest M8000, clutch equipped Shimano Deore XT rear derailleur - A true high performance drivetrain. The broad gear range combined with the lightweight package means this bike is also very capable on the XC race track.

Perhaps the most significant improvement on preceding models however are the incredible Mavic CrossRide wheels. They are a serious upgrade on this bike and absolutely unseen for a bike at this price point.  CrossRide wheels remove a lot of weight from the rotating mass and feature sealed bearings, straight pull spokes with wider and lighter rims – ensuring that these wheels will be your loyal companion for many kilometres to come

Key Features

  • ASX Advanced Alloy linkage driven single pivot XC frame with 4.7" of suspension travel (internal routed) and 2THRU axle system.
  • Tapered Head Tube
  • Rockshox Recon Gold Air fork, Travel 120mm, with remote lockout on handlebars
  • Rockshox Monarch RT Air rear shock with 2 position compression rebound adjustment
  • 22 Speed Shimano Deore XT / SLX group set
  • 27.5 inch Mavic CrossRide wheels with Schwalbe Smart Sam tyres.
  • 5 Year Warranty on frame
  • Full manufacturer’s warranty on parts
  • Weight 13.2kg (Medium frame including Pedals)


Model Comparison Chart


Siskiu D5

Siskiu D6

Siskiu D7

Siskiu D8

Forks SR Suntour XCM Hydraulic Lockout, Travel 120mm, coil SR Suntour XCR Air Fork, Travel 120mm, Hydraulic lockout Rockshox 30 Silver Solo Air, Travel 120mm Hydraulic lockout Rockshox Recon Gold with Remote Lockout,
Travel 120mm,
15mm thru Axle
Weight 14.5kg 13.9kg 13.5kg 13.2kg
Drivetrain Shimano Alivio/Deore Shimano SLX/Deore Shimano XT/Deore Shimano Deore XT/ SLX
Speed 27 Speed 30 Speed 2x10 - 20 Speed 2x11 - 22 Speed
Brakes Shimano BR-M315 Hydraulic Disc Brakes Shimano BR-M365 Hydraulic Disc Brakes Shimano M365 Hydraulic Disc Brakes Shimano Deore BR-MT500 Hydraulic Disc Brakes
Wheelset Araya DM-650 Doublewall alloy Araya DM-650 Doublewall alloy Araya DM-650 Doublewall Alloy Mavic Crossride 27.5"
Price $999 $1149 $1399 $1999
Extras SISKIU D5 - 2x9 18 Speed Option Available

Shimano Hubs

Rear thru axle 

Shimano Hubs

Rear thru axle

Front and rear thru axle

Remote fork lockout




Check out the link below for the review of the 2016 Siskiu D8 by Flow Mountain Bike. Please note the new 2017 version has an upgraded frame and is now 22 speed.

2016 Siskiu D8 Review - Flow Mountain Bike



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2017 Polygon Siskiu D8 (27.5 inch)

2017 Giant Anthem 3 (27.5 inch)



ALX Alloy Cross Country, 120mm travel front, 4.7" travel rear

Alloy Cross Country frame 4.0" travel

Similar (Polygon more travel and
rear thru axle)



Rockshox Recon Gold with Remote Lockout ,
Travel 120mm, 1-1/8” Tapered Steerer,
15mm thru Axle

RockShox Recon Gold RL Solo Air,
120mm Travel



Rockshox Monarch RT

RockShox Deluxe RT



Entity Expert, Alloy, 740mm

Giant Connect 31.8 Alloy



Entity Expert, Alloy 60mm

Giant Connect Alloy



FSA No.57B Internal Sealed Caged Bearing,
Tapered 44/56MM

Giant Sealed Bearing

Polygon better


Entity Assault Saddle

Giant Contact Forward



Entity Expert, Alloy, 30.9mm

Giant Connect, Alloy 30.9mm



Shimano SLX FC-M7000 34X24T

Shimano Deore 36x22T

Polygon better


VP Component VP-349, Alloy

None included

Polygon better


Shimano Hollowtech 2 Integrated

Shimano Press-Fit



Shimano SLX 11-42T  11 Speed

Shimano Deore HG50

Polygon better


Shimano SLX FD-M7020

Shimano Deore

Polygon better


Shimano Deore XT RD-M8000-GS

Shimano Deore

Polygon better


Shimano SLX SL-M7000 I-SPEC II - 22 Sp

Shimano Deore - 20sp

Polygon better


Shimano Deore BR-MT500

Shimano M365 Hydraulic

Polygon better


Schwalbe Smart Sam, 27.5”x2.25”

Schwalbe Racing Ralph

Giant better


Mavic Crossride 27.5"

Giant S-XC3 27.5

Polygon better


Stainless Steel Spokes




Mavic Crossride, sealed bearings

Giant Tracker, sealed bearings

Polygon better


Yes (some regional and  remote postcodes excluded)


Polygon better



$2,499 (Source: Giant Website AUS
Sept 16)

$500 Difference

Size Chart




RIDER HEIGHT 160-170cm 170-180cm 180-190cm
SEAT TUBE LENGTH 15.5" 17.5" 19.5"


Note: If you are in between sizes, measure your wingspan. If it is greater than your height, go for the frame size up. If your height is greater than your wingspan, go for a frame size down.



Siskiu D7

Sizes (A) Stack (mm) (B) Reach (mm) (C) Head Tube Angle (D) Head Tube Length (mm) (E) Head Tube Diameter (mm) (F) Seat Tube Angle (G) Seat Tube Length (C-T) (mm) (H) Top Tube Actual (mm) (I) Top Tube Effective (mm) (J) Front Center (mm) (K) Fork Offset (mm) (L) Rear Center (mm) (M) BB Height (Ground Clerance) (mm) (N) BB Height (BB Drop/Rise) (O) Stand Over Height (mm) (P) Rear Wheel Axle / O.L.D (mm) (Q) Seatpost Size (mm)
15 583 403 67.5 115 ZS44 | ZS56 74.5 385 549 565 684 44 438 331 22 Drop 673 142 x12 / 135 x 9 (2HRU Axle system) 30.9
17 583 423 67.5 115 ZS44 | ZS56 74.5 435 564 585 704 44 438 331 22 Drop 700 142 x12 / 135 x 9 (2HRU Axle system) 30.9
19 592 446 67.5 125 ZS44 | ZS56 74.5 485 589 610 730 44 438 331 22 Drop 736 142 x12 / 135 x 9 (2HRU Axle system) 30.9
20.5 592 466 67.5 125 ZS44 | ZS56 74.5 520 612 630 750 44 438 331 22 Drop 754 142 x12 / 135 x 9 (2HRU Axle system) 30.9


We understand how important shipping is once you click "buy now", that's why we have the following policies

Australian Warehouse

All products are in stock and ready to ship from our Sydney warehouse (with the exception of preordered bikes, which have the dispatch date illustrated)

Next day dispatch

All orders received by 5 pm AEST will usually be dispatched the following business day. If an order is placed on the weekend or public holiday, please note dispatch will usually be the next working day. For tracked shipments, please allow 12 hours for tracking to begin.

Shipping of Parts, Accessories and Apparel

Economy Shipping

There is free delivery available on all small parcels Australia wide using tracked services of Australia Post or Fastway, no minimum order value required! Estimated delivery time is 4-9 business days. 

Express Shipping

We do also offer Express Shipping for a small additional fee on parts, accessories and apparel orders. Estimated delivery time on Express Shipping is 1 to 4 business days.

Shipping of Bikes

Shipping of bikes and other bulky goods is free to 85% of residences in Australia. However, some postcodes incur a surcharge starting from $29. 

Once shipped you will be issued a consignment number which can be used to track your parcel. We use Direct Freight Express for deliveries and you can track your delivery by calling 1300 347 397 or online at www.directfreight.com.au


We’re so confident that you’ll love our extensive range of bikes, that we’ll let you ride one as your own for a full 14 days and if you don’t like it, simply e-mail us at sales@bicyclesonline.com.au and we’ll pick it up from you, free of charge! Just make sure you keep the box so it can be re-used to send it back. Click here for more information. 

All of our bicycles come with a Free Pro Build valued at $99. This means that your bicycle will be pre built by our professional mechanics. For your convenience, safety and comfort all our bikes are fully assembled prior to delivery. The bike is then packaged back into a box for secure shipment.


When your bike arrives, all you have to attach is the front wheel, the handlebar and pedals, everything else has been done – the headset has been adjusted, wheels trued, pedals and seat post greased, brakes and gears calibrated, and the tyres have been pumped up (please note upon arrival, in some cases you may need to add more air to tyres).

Most companies simply sell you the bike as it comes from the factory, which will require significant know-how to get your bike on the road. Currently we are the only Australian company providing this service, and have the 14 day test ride to back it up.

How does my bike arrive? Bicycles Online

All the tools required to assemble the bike are included. 

Please note, that all bicycles whether purchased online or instore, are mechanical devices and need to be serviced regularly to ensure proper functioning. New gear and brake cables, will stretch during the initial bed-in period, and will need to be adjusted after approximately 150-300km. 

Whilst your new bicycle will have already gone through our Pro Build process, you will still need to complete some minor final assembly steps when you take your bicycle out of its box.

Please follow the video playlist below to correctly complete the setup of your new bike:


Assembly Time:

  • 10-15min - You have assembled bikes before
  • 15-25min - You are mechanically handy
  • 30-40min - Never assembled a bike and working with tools isn't your thing


Unboxing your bike:

Start by carefully opening the top flap to expose the contents. You will see the bike with plenty of protective packaging and next to the rear wheel, the saddle & seatpost, a small cardboard box where your pedals, tools, bell and reflectors are. If you ordered any other products with the bike, it is likely they were placed on the bottom of the box as well. Remove all the loose items before pulling the bike out of the box and gently placing it on the floor.

Keep the box and all the protective packaging found on the bike in case you choose to change frame sizes, upgrade/downgrade the bike, or return the bike for a full refund under the 14 Day Test Ride Policy.


How to install a thru axle:


Disc Brake Setup:


How to Install Handlebars and faceplate:


How to install pedals on your bike:


Congratulations on your Purchase:

This bicycle is backed by a 5 year factory warranty on the frame and full manufacturer’s warranty on parts.

Warranty is valid only for bicycle that has been properly and well-maintained under the following conditions:

Warranty includes:

  • All damaged or fractured or broken frame / fork / component which was caused by manufacturing or assembling error in factory.
  • Non functioning mechanism caused by manufacturing error in factory.

Warranty is NOT valid for:

  • Incorrect assembly, i.e pedals installed in the wrong crank arm. 
  • Normal degradation caused by frequent use, such as degrading brake shoe, deflated tire, etc
  • Surface defects, such as stained, marred, defaced, etc
  • Damaged caused by misuse or accident
  • Other damages which are not caused by factory error
  • Bicycles which have been sold to another party
  • Bicycles used in commercial capacity, such as rentals
  • Bicycles which have not been well-maintained

For any damages which is guaranteed by Polygon as the first condition above, Polygon will repair or replace damaged frame / fork / component with the one of the same brand or similar.

Warranty is valid for all Polygon bicycles to the original owner only, by showing the purchase invoice.  

To make a claim click here.

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