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Borealis Crestone Eagle GX 12 speed Build

Borealis Crestone Eagle GX 12 speed Build
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We do not ship this item, however it can be reserved online and picked up at your convenience in our store. You will be notified as soon as your order is ready for pickup.


Since 2013, Borealis has specialized in lightweight carbon fiber fat bikes. The Crestone is our tried and true flagship model. Its frame geometry is optimized for riding in snow and sand with clearance for up to 5” wide tires. Paired with the most technically advanced components in the industry, the Crestone sets the standard for premium quality carbon fiber fat bikes.


Standard features include: SRAM Eagle NX 12-Speed drivetrain, SRAM Level T brakes, rigid carbon fork, carbon handlebars, carbon seat post, durable Sun Ringle Mulefüt rims and your choice of tires.
Frame geometry provides responsive handling, offering maximum control for varying conditions in snow or sand.
Tire clearance up to 26x5” and 27.5x4.5”.
Compatibility for 100-120mm of suspension travel for more technical riding.
Lightweight, durable carbon fiber frame comes with internally routed cables, 2-3 bottle cage mounts and lizard skin protectors on both the down tube and drive-side chain stay.

Rockshox Bluto Fork tire size limitations: 26x5” or 27.5x4”
Mastodon Pro EXT Fork tire size limitations: 26x5” or 27.5x4.5”
Borealis Rigid Carbon Fork tire size limitations: 26x5” or 27.5x4.5”
Dually 29x45 and 27.5x45 Rims – Max tire width: 3”
All rims 65mm to 85mm wide are compatible with tire widths of 3.8” to 5”
HED Carbon 100mm Rims – Max tire width of 4.6”

Based on our research, riders at the heights below will usually take the corresponding frame size. If you’re at a transitional height that spans two sizes, look at the geometry chart to get the Stack and Reach you like based on other bikes you are comfortable.

Borealis offers four frame designs with unique fit and geometry to suit your every Fat Bike need. Begin by taking a rough size approximation on the chart below that is based on height, then select the corresponding bike with your fit needs by using the geometry chart further below. We recommend a similar fit to you mountain bike, so grab a measuring tape and dial it in.

EFFECTIVE TOP TUBE 23.02 in 24.02 in 24.8 in 25.59 in 585 mm 610 mm 630 mm 650 mm
SEAT TUBE CENTER TO TOP 15 in 17.01 in 19.06 in 21.02 in 381 mm 432 mm 484 mm 534 mm
HEAD TUBE 4.13 in 4.72 in 5.31 in 5.91 in 105 mm 120 mm 135 mm 150 mm
SEAT TUBE ANGLE 73 deg 73 deg 73 deg 73 deg 73 deg 73 deg 73 deg 73 deg
HEAD TUBE ANGLE 70 deg 70 deg 70 deg 70 deg 70 deg 70 deg 70 deg 70 deg
STANDOVER HEIGHT Due to various rim and tire options stand over is not identified.
CHAINSTAY 17.91 in 17.91 in 17.91 in 17.91 in 455 mm 455 mm 455 mm 455 mm
BB DROP 2.36 in 2.36 in 2.36 in 2.36 in 60 mm 60 mm 60 mm 60 mm
REACH 16.04 in 16.65 in 17.22 in 17.76 in 407.3 mm 423 mm 437.5 mm 451.2 mm
STACK 23.50 in 24.05 in 24.61 in 25.16 in 597 mm 610.9 mm 625 mm 639.1 mm


Frame Borealis Carbon, Internal Routing w/ Bottle Cage Mounts
Fork Borealis Rigid Carbon fit tire up to 26x5" or 27.5x4.5"
Headset Borealis
Rear Shock N/A
Rims/Wheels MuleFut 27.5x65
Hubs Borealis: Front 15x150, Rear 12x197 w/XD Driver
Spokes Wheelsmith Black
Tires 45N Dillinger 27.5x4.0 Tubeless Ready Folding
Crankset SRAM Eagle GX
Chainwheel 30 Tooth
Bottom Bracket SRAM Dub 100
Chain KMC X12
Front Derailleur N/A
Rear Derailleur SRAM Eagle GX
Rear Cogs GX 12spd 10-50t
Shifters SRAM Eagle GX1
Handlebars Borealis Carbon SL
Tape/Grips Borealis
Stem Borealis Alloy
Brake Levers SRAM Guide RS G2
Brakes SRAM Guide RS G2. Rotors: Avid Centerline 180/160
Pedals N/A
Saddle Borealis
Seat Post Borealis Carbon
Seat Binder Borealis Alloy
Accessories & Extras Downtube and Chainstay Protectors

* Subject to change without notice.


Getting FAT | A Fat Biking Story

6 years ago, Dave Ochs, John Norton, and Steve Kaczmarek helped found the Borealis Fatbike World Championships. Today, it's in its 5th year with over 750 riders having participated in the elite division and over 1,400 competitors in all of the various races during worlds. This is that story.

Part Numbers

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