Borealis is relatively new to the fat bike market, but made a very big impression with the introduction of the Yampa and Echo. The Crestone is a refinement of those technologies, with improved geometry, frame design elements, and quality craftsmanship. Much of what was missing on the Yampa can be found on the Crestone after months of rider and market input. The rear QR was finally replaced with a proper thru axle. The rear carbon dropout was reinforced. The standover clearance was decreased. The “calf-bang factor” was improved. Overall geometry improved, making a much more capable bike. You can check out details of the Crestone here on their webpage.

A nice looking ride, the Crestone is redesigned for more aggressive riding while keeping the race-oriented riders in mind — A nice-looking ride, the Crestone is redesigned for more aggressive riding while keeping the race-oriented riders in mind

The Deets (from Borealis)

The Crestone is a closed mold, carbon fiber bike frame that represents the most advanced geometry for fat bikes.

New impact and fatigue standards to match the demands of riders who might ride a fat bike more aggressively

Totally new frame design developed to be more durable and thrilling to ride, while maintaining an aesthetic becoming of a high performance product

Weighs in at 150 grams less than the Echo

Available in two new colorways

Advanced carbon molding with state of the art production

Designed with reduced stand over height–top tube drops by one half inch

Available with SRAM XO1 or XX1 components

Internal routing ports galore adorn the Crestone, but plug these up or water will find it's way into the frame — Internal routing ports galore adorn the Crestone, but plug these up or water will find its way into the frame

Geometry and Sizing

I was sent a size-medium frame after perusing the geometry chart, which is the same size that I typically ride. Top tube and seat tube height are important, but standover height and reach are my main concerns when sizing a bike. The geo is pretty spot on and summed up well in this chart from Borealis:

	S	M	L	XL	S	M	L	XL
Effective Top Tube	23.02 in	24.01 in	24.67 in	24.72 in	584.8 mm	609.8 mm	626.6 mm	627.9 mm
Seat Tube Center to Top	15.04 in	17.01 in	19.06 in	21.02 in	382 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	18.07 in	18.07 in	18.07 in	18.07 in	459 mm	459 mm	459 mm	459 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 has been working hard on shoring up their carbon while making a capably-light frame, and it shows.

The color I was sent pays homage to the Colorado flag, and the paint stands out with a lot of pop.

Ode to the Centennial state, the Crestone has paint that looks superb

Components

Borealis was kind enough to send over the top-shelf XX1 build for review, spec’d with a Bluto and the new Maxxis Minion FBF 4.8s. Despite being a relatively-light frame using the lightest components possible, the build came in at just over 29.8lbs with flat pedals (without a dropper), due mainly to aluminium wheels and large, meaty Minions. The tires alone weigh 3.6 lbs, each! Despite the weight, it was a solid build that never felt heavy.

The Maxxis Minion FBF 4.8s are on the hefty side at 1620 grams, but have a lot of traction, float well, and paddle well.

Cockpit

Borealis spec’d this ride with a feathery but stout RaceFace NEXT 750mm bar and 70mm RaceFace stem, Ergon grips, Ergon saddle, and lightweight NEXT carbon post. No quick release was included on the post, which would be a nice addition given the lack of a dropper.

A 70mm stem holds teh RaceFace bars and is solid — A 70mm stem holds the RaceFace bars and is solid

Brakes

I was delighted to see that this bike came with the new SRAM Guide ~~RSC~~ Ultimate brakes. I have had SRAM Guide RSC brakes installed on my personal bikes for the past year, including my personal fat bike. These are quiet, modulate well, and stop on a dime. For a comprehensive review of these brakes, look here. I’ve tested the RSCs on the singletrack, at the DH park, and on several fat bikes.

Drivetrain

Borealis spared no expense with the lightest, most versatile crankset on the market: the RaceFace NEXT SL. I have also had a lot of experience with these, which I will expound upon in my final review, and compare it to other bikes I have tried them on. They also supplied a gold KMC chain mated to a RaceFace machined 30T chainring, XX1 cassette, and XX1 rear derailleur. An XX1 shifter handles the tranny.

Super light and stiff cranks, the Next SLs are lustworthy

Fork

The newest model of the RockShox Bluto with the RTC3 came with the Crestone, which was set at 100mm of travel and has quite a bit more adjustment than the first generation of the Bluto, which I reviewed here.

Wheels

Borealis included the house-branded 80mm Turnagain hubs laced to beautiful, shiny, anodized blue Turnagain hubs. The hubs are 150mm in the front to accommodate the width of the Bluto, and 197mm in the rear. This, along with wide stays, allows 5 inch tires to clear with ease if the beefy Minion 4.8s aren’t enough to float your boat. The Minions are supple with a 120tpi casing and have very aggressive knobbies. I set these up tubeless immediately, and the Minions were by far the easiest tubeless tire to mate to any rim I’ve tried.

The hubs are gorgeous, have a discernable click when freespinning, and seems to have very quick engagement — The hubs are gorgeous, have a discernable click when freespinning, and seem to have very quick engagement

Here is a complete summary of the build from the Borealis website:

Frame	Borealis Crestone
Fork	Borealis Carbon Rigid Fork
Headset	Cane Creek 40
Hubs	Turnagain: Front 15×150 Rear 12×197
Rims	Turnagain FR 80 FTD Tubeless
Spokes	Wheelsmith Black DB
Nipples	Wheelsmith Black Alloy
Rim Strips	Turnagain RS80
Tires	26×4.8″ Maxxis Minion FBF EXO TR
Tubes	Turnagain MagnumFAT
Bar	Race Face Next SL 35 740mm
Stem	Race Face Turbine 70mm
Post	Race Face Next SL 31.6mm
Saddle	Ergon SME30 EVO “Borealis”
Grips	Ergon GA2
Crankset	Race Face Next SL 30t 175mm
Front Derailleur
Rear Derailleur	SRAM XX1 11 Speed
Chain	KMC X11
Cassette	SRAM XG-1199 10-42
Shifters	SRAM XX1 11 Speed
Brakes	SRAM Guide Ultimate w/Centerline 180/160
DT/CS Protector	Lizard Skins

MSRP: $5,850

MSRP with a RockShox Bluto Fork: $6,050

I have already put some miles in on this bike and cannot wait to log some more! Let me know what questions you may have, and I will do my best to answer them during my final review. Thanks!