Polygon Collosus DH8 - Downhill Mountain Bike

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Introducing the new Polygon Collosus DH8 mountain bike. There has been 3 years of development into this new DH frame which recently Kurt Sorge rode to the 2017 Redbull Rampage victory.

The new Colossus DH frame and suspension system has been carefully redesigned by the engineers at Polygon and with intensive feedback from the UR Team racing the DH World Cup Championships. In particular, Australians Mick Hannah “Sik Mik” and Tracey Hannah had a pivotal role in creating this new frame, with now better traction over rough sections, better pedalling efficiency, and a more precise steering feedback. The rear suspension system is now more progressive and the shock ramp up has been fine tuned. To increase rear end stiffness, the rear triangle is now made out of Polygon’s proprietary ACX Carbon, which was moulded and shaped to be extremely stiff laterally, soak up small vibrations and bumps better, keeping the rear wheel grounded for better traction, and also the added benefit of shedding weight from the frame. Testing wheel sizes was also a huge deal in making the Polygon Collosus DH8, with Polygon testing 26”, 27.5” and even 29” wheels. In the end, 27.5” wheels (or 650b) were the clear winners, offering extra speed on the flats, soaking up the punishment of rock gardens with ease and allowing to build a super nimble bike to tackle the most demanding technical sections in the Downhill World Cup calendar.

Part of the Polygon Collosus DH8’s appeal is the value you get when considering all the parts and components on this bike. Drivetrain and Brakes from Shimano Zee are most likely the best value downhill components out there, with tremendous durability, reliability and built specifically for the demands of frequent downhill riding. In fact, little separates Shimano Saint components from Shimano Zee these days, apart from weight and less range on Saint components. When you’re riding Zee, you know you have at your fingertips on some of the best technology available to Downhill riders.

An Integral part of a downhill rig is the shock and fork, and the Polygon Collosus DH8 does not disappoint. In fact, the suspension fork you find on this bike is the Rockshock Boxxer Team which is often seen on some other brands top of the line rigs. This is a Giant improvement on last years Colossus DH2 while still maintaining a price point that won’t break the budget. With an Air and Coil Spring System, Fast Black Stanchions and the lightest weight DH fork on the market right now, the revamped Rockshock Boxxer is now one of the best downhill forks on the market. Paired with a Rockshock Vivid R2C shock, the Polygon Collosus DH8 leverages the best R&D from Rockshox to complete a suspension setup allowing for optimal performance.

Completing the build, a Spank Spike Race28 DH Evo wheelset would be the most understated component on this Polygon DH8 and possibly the one that you will be most grateful for when riding. The tubeless rims with Dynamal and Oohbah technology are light are extremely sturdy, triple butted spokes and the reliable Novatec hubs make this a wheelset that wants to be punished on fast rock gardens, tested on big jumps and steered right into tight, sliding corners.

Kore completes the finishing kit with durable components, bars, stem and seatpost, giving you an extra boost of confidence to rail the next berm at full speed.

The Polygon Collosus DH is this year’s biggest release for Polygon Bikes and the DH8 proves just that.

Check out the video below for more info on the Polygon DH frame development:

and another video of Kurt Sorge shredding on the DH8 in Bali



  • ALX Advanced Hydroformed 6061 Aluminium Downhill Frame with ACX Carbon Rear Triangle 
  • Floating Suspension System 3 technology (FS3)
  • Full Shimano Zee 640 componentry
  • RockShock Boxxer Team front fork
  • RockShock Vivid R2C rear shock
  • Kore Torsion handlebar and stem
  • Spank Spike Race28 DH wheelset
  • Schwalbe Magic Mary 27.5" x 2.35" tyres
  • 5 Year Warranty on frame
  • Full manufacturer’s warranty on parts




Comparison  POLYGON COLLOSUS DH8 Giant Glory 27.5 1 Comments
FRAME ALX Advanced 6061 Hydroformed Aluminium front triangle with ACX Carbon Rear triangle - Downhill FS3 suspension System ALUXX SL Alloy, 8"/203mm Maestro suspension Polygon with Carbon Rear Triangle
FORK RochShox Boxxer Team RockShox Boxxer Team Same
REAR SHOCK RockShox Vivid R2C RockShox Vivid R2C Same
HANDLEBAR Kore Torsion M35, 800mm Giant Contact SL DH Polygon better
STEM Kore Torsion 30mm Giant Contact SL DH, Direct Mount Polygon better
SADDLE Entity Assault Giant Contact Similar
SEATPOST Kore Aerox 3, 30.9x300mm Giant Contact SL, 30.9mm Polygon better
CRANKSET Shimano Zee FC-M640 36T 165mm Truvativ Descendant, 36T Polygon better
BOTTOM BRACKET Shimano Hollowtech II Truvativ GXM TM integrated Similar
CHAINGUIDE e*thirteen LG1+ MRP G3 Mini Chain Guide Similar
CHAIN Shimano XT CN-HG95 KMC X10 Similar
CASSETTE Shimano CS-5700 11-25T Sram PG-1050 11-26T, 10sp Polygon better
SHIFTING LEVER Shimano Zee SL-M640 Sram GX Polygon better
REAR DERAILLEUR Shimano Zee RD-M640SS Sram GX Polygon better
BRAKE Shimano Zee BR-M640 Sram Guide R Polygon better
PEDAL Kore Torsion SX V2 N/A Polygon better
TYRE Schwalbe Magic Mary 27.5" X 2.35” Schwalbe Magic Mary 27.5x2.35 Same
WHEEL SET Spank Spike Race28 DH Evo Giant P-AM2 Polygon better
Price $3,999 including delivery $4,999 $1,000 difference
Size Chart





RIDER HEIGHT 155-165cm 165-175cm 175-185cm 185-195cm
SEAT TUBE LENGTH 15" 16" 17" 18"


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.



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) (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 (S) Low BB 595.1 377.6 62.8 110 Tapered 50/44~62/56 62.8 383 476.8 536 743.3 442.8 361.4 2.9 Rise 725.1 12 x 157 30.9
15 (S) Hi BB 593.4 380.3 63.1 110 Tapered 50/44~62/56 63.1 383 476.8 534.8 743.3 441.5 364.7 6.2 Rise 728.5 12 x 157 30.9
15 (M) Low BB 595.1 397.6 62.8 110 Tapered 50/44~62/56 62.8 383 494.8 556 763.1 442.8 361.4 2.9 Rise 724.8 12 x 157 30.9
15 (M) Hi BB 593.4 400.3 63.1 110 Tapered 50/44~62/56 63.1 383 494.8 554.8 763.3 441.5 364.7 6.2 Rise 728.3 12 x 157 30.9
15 (L) Low BB 595.1 425.3 62.8 110 Tapered 50/44~62/56 62.8 383 519.9 583.8 791 442.8 361.4 2.9 Rise 724.7 12 x 157 30.9
15 (L) Hi BB 593.4 428 63.1 110 Tapered 50/44~62/56 63.1 383 519.9 582.5 791 441.5 364.7 6.2 Rise 728.1 12 x 157 30.9
15 (XL) Low BB 595.1 447.3 62.8 110 Tapered 50/44~62/56 62.8 383 540.1 606 812.4 442.8 361.4 2.9 Rise 724.7 12 x 157 30.9
15 (XL) Hi BB 593.4 450 63.1 110 Tapered 50/44~62/56 63.1 383 540.1 604.5 813 441.5 364.7 6.2 Rise 728.1 12 x 157 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.

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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