2019 Polygon Siskiu N8 Dual Suspension Mountain Bike

WAS $3,499.00 You Save $500.00

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Key Features

  • ALX Enduro Alloy Boost frame with 170mm (27.5") / 160mm (29") of suspension travel (internal routed)
  • Tapered Head Tube
  • Rockshox Yari RC DebonAir Boost front air fork
  • Fox Performance Float DPX2 air shock with external rebound and 3 position compression
  • 1 x 12 SRAM NX Eagle drivetrain
  • Tektro Orion 4 Piston Hydraulic disc brakes
  • EXA Form Drive Dropper seat post
  • Entity XL2 tubeless ready wheelset with Schwalbe Nobby Nic tyres.
  • 5 Year Warranty on frame
  • Full manufacturer’s warranty on parts
  • Weight = 14.9kg (Size M)
Building on the tremendous success of the Siskiu D and more recently the Siskiu T range over the past few years, we are excited to introduce you to the newest and burliest member of the Siskiu family - the Siskiu N - Polygon's latest alloy all mountain / enduro steed. The Polygon Siskiu N8 is the bike you've been waiting for and it comes with all the parts and clever technology you'd expect from Polygon, like the frame size specific 29er or 27.5" wheels, internal dropper post, Rockshox Yari front fork suspension and a 1x12 drivetrain. 
The Siskiu N is built around a new lightweight, hydroformed 6061 aluminium Boost frame and longer 160mm (29er) / 170mm (27.5") travel. By utilising a one piece linkage system, Polygon have been able to keep the frame weight down whilst reinforcing high-stress areas and reducing flex under heavy loads. The rear swing triangle also features a unibody pivot bridge that stiffens the rear wheel and provides you a lot more control when exiting high-speed corners and negotiating rock gardens. The Boost design means that Polygon have been able to include wide 29mm rims with 2.6" tyres (27.5" wheel) and 2.35" tyres (29" wheel). The frame is finished off with a tapered headset, rear thru axle, and internal routing for gears, brakes and dropper seat post.
The  Siskiu  N series utilises  Polygon's new Wheel Fit Size System whereby each frame size is paired with the wheel size that best fits the rider and sets them up for optimal efficiency and power transfer. We pair 29er wheels with 18.5" and larger bikes, and more proportional, better-fitting  27.5-inch  wheels for 17.5" and smaller bikes.
A new SRAM NX Eagle 1 x 12 drivetrain powers the N8 with a massive 50T rear cassette providing plenty of range to glide up those steep climbs. A single trigger shifter keeps things simple while providing smooth, quiet action and reliable chain retention (thanks to a single chainring and rear-derailleur clutch). The Descendant crankset is engineered for complete chain control. Each tooth’s thickness is precisely toleranced and controlled to work seamlessly with the SRAM chain’s inner and outer links eliminating the need for a bulky chain guide and continuing the clean looks of the bike.
Dampening duties on the N8 are provided by a Rockshox Yari DebonAir front fork. This is combined with a dependable Fox Performance Float DPX2 air shock on the rear with external rebound and 3 position compression. The bike rolls on a pair of wide 29mm rim Entity XL2 tubeless ready wheels and Schwalbe Nobby Nic tyres with a nice and wide 2.35" to 2.6" width giving you loads of traction for climbs and hitting the berms.
Completing the Polygon Siskiu N8 is an EXA Form Drive dropper seat, Entity Xpert cockpit, and Tektro Orion 4 Piston Hydraulic Disc Brakes. 

Model Comparison Chart


Siskiu N8

Siskiu N9


ALX Alloy Boost Enduro frame with 170mm (27.5") / 160mm (29") of suspension travel (internal routed), Tapered headtube

ALX Alloy Boost Enduro frame with 170mm (27.5") / 160mm (29") of suspension travel (internal routed), Tapered headtube


Rockshox Yari RC Debon Air Boost fork, Travel 170mm (27.5") / 160mm (29"), External rebound, low speed compression, 15mm thru axle

Fox 36 Rhythm Boost Air Fork
Travel 170mm (27.5") 160mm (29"), Tapered Steerer,
15mm thru Axle 


Fox Performance Float DPX2 E2E:205x65 Trunnion

Fox Performance Float DPX2 E2E:205x65 Trunnion

Drivetrain SRAM NX Eagle SRAM GX Eagle
Speed 1 X 12 Speed 1 X 12 Speed
Brakes Tektro Orion Hydraulic Disc Brakes TRP Slate 4 Piston Hydraulic Disc Brakes
Wheelset Entity XL2 Disc 29-584 (27.5”) / 29-622 (29”), tubeless ready Entity XL2 Disc 29-584 (27.5”) / 29-622 (29”), tubeless ready
Weight 14.9kg 14.6kg
Price $3,499 $3,899

EXA Form Drive Dropper seat post

EXA Form Drive Dropper seat post



Polygon Siskiu N8 (27.5 inch or 29er)

2018 Trek Remedy 7 (27.5 inch)



ALX AM / Enduro Alloy Boost frame 170mm travel (27.5”) / 160mm travel (29”),
Tapered headtube

Alpha Aluminium Boost frame 150mm travel

Polygon more travel


Rockshox Yari RC Debonair Boost 15x110mm, 170mm (27.5") / 160mm (29") Travel

Rockshox Yari Solo Air Boost 160mm travel

Polygon better


Fox Performance Float DPX2 Air shock

Rockshox Deluxe RL Air Shock

Polygon better


Entity Xpert, Alloy

Bontrager 31.8 Alloy



Entity Xpert, Alloy

Bontrager Rhythm, Alloy



Entity Assault Saddle

Bontrager Evoke



EXA Form Drive SI Dropper Post (125mm S-M, 150mm L-XL), Zero offset, 30.9mm

Bontrager Dropper post, 30.9mm



Truvativ Descendant 6K Aluminum Eagle 32T Narrow-Wide Boost


Polygon better



None included

Polygon better



Press-Fit 92

Polygon better


SRAM NX 1230 Eagle 12 Speed 12-50T

SRAM NX Eagle 11 Speed

Polygon better






SRAM NX Eagle 12 Speed

SRAM GX Eagle 11 Speed

Polygon better


SRAM NX Eagle 12 Speed

SRAM GX Eagle 11 Speed

Polygon better


Tektro Orion 4-Piston Hydraulic 180mm rotors

SRAM Level T



Schwalbe Nobby Nic, 27.5”X2.60” / 29”X2.35”

Bontrager XR4 27.5"x2.4"

Polygon better


Entity XL2 Disc 29-584 (27.5”) / 29-622 (29”), tubeless ready

Bontrager Line Comp, tubeless ready



Stainless Steel Spokes




Entity, sealed bearings

Formula sealed bearings



Yes (some regional and  remote postcodes excluded)


Polygon better



$3,699 (Source: Trek Website AUS
July 18)

$200 Difference

Size Chart




RIDER HEIGHT 155-170cm 170-180cm 180-190cm 190-200cm
SEAT TUBE LENGTH 15.5" 17.5" 18.5" 20"
WHEEL SIZE 27.5" 27.5" & 29" 29" 29"


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.



  A B C D E F G H I J K L M
Model Size Seat Tube Length Seat Tube Angle Effective Seat Tube Angle Head Tube Length Head Tube Angle Effective Top Tube BB Height BB Offset Chainstay Length Wheelbase Frame Reach Frame Stack Standover Height
SISKIU N Small (27.5") 400 75 71.5 100 65.5 563.8 355 5 Drop 435 1153.9 405 592.7 720.7
  Medium (27.5") 430 75 71.5 100 65.5 593.8 355 5 Drop 435 1183.9 435 592.7 718.8
  Medium (29") 430 75 69.5 90 65.5 600.1 343.5 33 Drop 439.4 1194.9 435 616.1 720
  Large (29") 470 75 69.5 102 65.5 624.5 343.5 33 Drop 439.4 1221.1 456.6 626.1 743.1
  Extra Large (29") 520 75 69.5 115 65.5 656.2 343.5 33 Drop 439.4 1255.3 485 638.8 773.7


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.

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 the brand as the first condition above, the brand will repair or replace damaged frame / fork / component with the one of the same brand or similar.

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

To make a claim click here.

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