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The crew at Borealis is adamant — fat bikes are for year-round use, on all kinds of trails and conditions. Having ridden them in both winter and summer, atop snow and desert sand and rock, we’d have to agree. The traction and flotation you get from a 4-inch tire just can’t be matched. And paired with Borealis’ carbon fiber design, it’s a high-performing, fast, and agile traction machine.

Up first need to be the axle standards — if you thought mountain bike axles and bottom brackets are a sea of ever-changing "standards," you ain’t seen nothing yet. The Borealis Yampa has a 197mm rear hub, which’ll build up a dishless rear wheel, and a 135mm front hub, with a 10mm bottom bracket shell sitting in between. The reason for these three standards is pretty simple — strength, tire clearance, and chain clearance. We mentioned the dishless rear wheel, but the Yampa will clear a 4.8in tire on a 100mm rim, and to do that, the crankset needs to be offset a bit to the outside, thus the 100mm BB.

The build is rounded out with SRAM’s X0 and X9 components, BB7 mechanical discs, a Race Face crankset, and Truvativ cockpit. The wheels start with Borealis’ own hubs, which are laced to Surly Turnagain rims, which have Surly Knards mounted to them.

  • Full carbon frame
  • Full carbon fork
  • Three water bottle cage mounts
  • 197mm rear spacing
  • 135mm front spacing with 15mm thru-axle
  • SRAM drivetrain
  • Surly rims and tires laced to Borealis hubs
  • Clearance for 4.8in tires on 100mm rims
  • Reviews
  • Q & A

What do you think about this product?

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Great ride...

  • Familiarity: I've used it several times

I wanted a bike that would break up my rides in the winter on rollers in the basement. Haven't had it during the winter yet but riding it in back country has been an absolute blast! No terrain... hills, dirt, mud... is an issue that it doesn't plow right through. Hills, rather up or down, is a breeze. I love it!

Fun to ride

  • Familiarity: I've used it several times

I ride a lot of single track, gravel roads and ATV. trails, the Borealis Yampa really handles these trails nice. Goes over rock gardens with ease and rolls thru ruts as well. The Borealis looks great black bike with red trim and wheels I love the red wheels. I cannot believe the bike was under $2300 just unbelievable price and it was easy to setup right out of the box.

Makes me smile

  • Familiarity: I've used it several times

Purchased from CC this past winter, initially just to ride in snow.

Huge props to CC/BC - 3rd bike i've purchased from them and everytime price, service, delivery, etc. have been terrific.

Re bike - put a few hundred miles on it; snow, dirt, sand/beach. Obviously takes some getting used to w/ larger tires etc., but bike is (relatively speaking) light as feather, handles super well, and is a blast to ride. As others have indicated, soaks up roots and rocks really well. I liken it to riding a sofa over some of the bumpy stuff. It's a blast in the snow and lots of fun riding on the beach.

My only complaint - and it's not really a complaint as i knew what I was getting as I bought the bike on sale and at a large discount - is that I'd love to change the drivetrain to a 1X... XOX9 is fine/dependable however.

FWIW, I don't find the red rims particularly outlandish and they pair nicely w/ the red/black frame... and I'm older than Paul below.

The Phat fat bike!

    I had the opportunity to ride this bike at Outerbike in Moab this year and had an absolute blast on it. The bike was so light weight and agile i totally forgot i was riding a rigid fatbike. If you are in the market for something to ride over the winter months in the snow or in the sand this is definitely the fatbike to get!

    If you have any specific questions feel free to hit me up direct at 801-736-6396 x 4074 or

    The Phat fat bike!

    First fat bike

    • Familiarity: I've used it once or twice and have initial impressions

    Received my yampa a few days ago. Everything was packaged very well and I was able to put it together quickly and everything was already adjusted perfectly. Mainly bought it for winter riding but took it out on some dry single track today and was surprised how much grip I had on downhills. The bike just eats up roots and rocks and spits em out. Also climbs like a goat. I am definitely hooked and will be riding it more than just in the winter. It's a great bike especially at the lower price. The only downside is the heavy 27 tpi knards that come with the bike. Swapped them out for some panaracer fat b nimbles and took over 2 lbs out of the bike.

    BRIGHT RED RIMS - Without a Warning.

    • Familiarity: I returned this product before using it

    I received my Borealis Yampa on Friday 6/19/2015. I was very excited to receive it as I had spoken to the Customer Service Reps at Competitive Cycle many times and confirmed the color, size, etc.

    HOWEVER, when I received the bike, I was shocked to find-out that it came with BRIGHT RED RIMS. I even asked the Customer Service Rep twice about the color scheme before ordering because I had read some bad reviews on Yelp concerning other products.

    Needless to say, I called CC right away and was told that Borealis is shipping all the Yampa's with these bright red rims now. They said they sent-out an e-mail informing everyone, but my bike had already been shipped.

    The bike seems like a nice ride, but I am 47 now and the red rims are just to much bling for me.

    The Customer Service Rep said he would take care of me and would "make it right". However, the only option I was given was to send the bike back for a refund.

    Nothing like wasting MY TIME for their MISTAKE. So now I have to box it back up and send it back. What a pain. Things like size and color matter...especially when the bike is almost $2,400. For $2,400 I expect to receive what I ORDERED.

    I would beware of CC as they do not have their act together. You would think that someone would have noticed the bright red rims were not stock while they were "building" the bike...but I guess that is too much to ask.

    If you want a bike with lots of bling, then I suggest the bright red rims. However, if you want something more subdued, then I would suggest calling them directly before ordering to find-out what you are getting for your money.

    I ordered Black with Red. I asked if they could just exchange the red rims for the correct black ones and they said they did not have any black rims to send me. So I do not know what you will receive if you order the Black with White color. They just told me the Yampas are coming with red rims now. I guess Borealis must have had an overstock of red rims and they thought no one would notice. Anyway you cut it, I'm not a happy customer.

    I had the same issue as Paul but they did email me to tell me that the rims would be different. I debated on canceling myself but felt it was a good price and with the savings upgraded to a 1x and some other changes. I was VERY disappointed too with the rims, for me more because of weight and I would have much preferred the marge lites. The upside is I feel more inclined to in put on bigger tires with the wider rim. I ordered the bike based on a friend ordering the black and white and his did come with the marge lite rims...big weight difference. At minimum, by now, they should update this site with correct information.

    First fat bike and now I am hooked!

    • Familiarity: I've put it through the wringer

    So I had not bought a new bike since my 1993 Gary Fisher MTB (decided motorcycles and snowmobiles were a better investment at the time), so fast forward to today and I have now had my Yampa X0/X9 for 10 days (keep that in mind when you read my feedback as I likely have no clue what I am talking about).

    After getting it setup I took it for a couple quick loops on the paved and very mild trails around the house and overall seemed fine. Then today I did a 10 mile ride which was a combination of mud, hard pack, 4' tall prairie grass (sucked), and more water crossings than I can a word the bike did AWESOME! I was blown away at how well it allowed me to point at just about anything and GO! For a non-front suspended hardtail I thought it rode great and now want to try the Borealis Echo just for comparisons (Bluto). I cannot wait until the trails are covered in snow to update this review but very early dirt trail impressions are positive. My only gripe is the brakes...likely going to switch to some hydro's, not sure which ones yet and the Turnagain rims are supposedly a pain, if not impossible, to turn tubeless...haven't tried just yet but will deal with that in the fall.

    Overall, got a great deal on the bike, like it a lot so far and would certainly purchase it again based on early impressions.

    UPDATED: 1/7/16

    Well thought I'd update the review given I now have around 500 miles of dirt, hardpack, mud and snow ridding on the Yampa. In summary still love it. The snow riding is a blast although the Surly Knards 3.8" that came with the bike suck in the snow...they are awesome and roll fast on the dirt but for winter riding I put on some 45nrth Dillinger 5's...along with some pogies (best money spent in cold weather). I also put a Wolftooth 1x setup on the front and ditched the front 2x...cleaner and less screwing around with adjustments. Only grip and this is a minor one is for some reason the "carbon creak" on this bike seems to be very the point I am going to strip the bike down completely this spring to redo it; was hoping that would be after owning it at least a full year but the noise is annoying the #$%@ out of me.

    First fat bike and now I am hooked!

    Just in Fat is Fast!

    • Familiarity: I've used it several times

    Wow, that was New and unexpected. Just slayed a night ride on our demo rig, umm wow. I am blessed to be able to try and ride the best of the best. I currently rock a Pivot Mach 6 27.5 and am pretty enthusiastic about it. However this brought back that first feeling of aww I had when I first started working in shops. It was New, different , and inspiring. Who needs suspension , it takes a lot of maintenance. This feels like that, has better traction, is laterally responsive for the climbs, and you just point and shoot and it delivers.

    Crazy fun, totally want one, with some minor additions. A dropper post is a must, and it would be nice having larger rotors, 180 would do the trick. As mentioned already it is worth getting the 29+ wheels for faster rides. But the enjoyment of the super cushy big fat tires is just rad, so depends on your riding style.

    Feel free to contact me directly should you want to make any of these changes and get one on order! 801.736.6396 x 4769 Or

    See ya out there!

    Just in Fat is Fast!

    The tube was not a surly tube.


      I've bought a yampa x0 / x9.

      I've removed the tire to the wheel replaced.

      But I was surprised.

      The tube was not a surly tube.

      The tube was not only fatbike.

      General was a bike tube.(kenda26x2.4/2.75]

      Tubes do not feel the funk something is, it's a really good thing.

      So I bought the bike only fat tube.

      I think it's wrong.

      The tube was not a surly tube.


      That tube will work for a fat bike wheel as it is approximately a 3 inch tube. Sometimes, for small parts, manufacturers will make substitutions that do not have a negative impact on performance.

      Please let me know if you have any other questions.

      Fun Bike and worth every penny!

        I had the opportunity to ride this bike at Outerbike in Moab this year and had an absolute blast on it. The bike was so light weight and agile i totally forgot i was riding a rigid fatbike. If you are in the market for something to ride over the winter months in the snow or in the sand this is definitely the fatbike to get!

        If you have any specific questions feel free to hit me up direct at 801-736-6396 x 4074 or

        Fun Bike and worth every penny!

        Great Bike

        • Familiarity: I've used it several times

        This is a great Bike, I use it in the beach, in gravel road and for a medium dfficulty down hill.

        It is light, ride almost over everything and the big wheels replace the suspention.

        Great Bike

        Take On The Tundra

        • Familiarity: I've used it once or twice and have initial impressions

        I am not a winter person. My last two winters in Utah have been spent hibernating or occasionally skiing.

        I was apprehensive about riding in the snow and not expecting to have fun on board the Yampa.

        After five minutes, my apprehensions were gone. The Yampa is pure fun and like nothing I have experienced before. A few spots on the trail pot marked by horses and bison became a challenge other than that, it climbs like you would expect a carbon hardtail to climb, descends with the cushioning of a full- suspension mountain bike, and rallies through ice, snow, and mud. It’s a perfect machine for taking on the Utah tundra. Borealis hit a home run with the Yampa.

        At 5'6 I feel comfortable on a medium

        Take On The Tundra

        You Need This Bike

        • Familiarity: I've used it once or twice and have initial impressions

        You may not know it yet, but his is your next bike. Whether you have a Fatbike or considering your first, this is the penultimate Fatbike experience. The carbon frame is a magnificent form that is lightweight and functional. If you already have a Fatbike, then you crave a Borealis because it's lighter than whatever you're riding. If your the uninitiated then you can head straight to first class.

        I rode this bike on singletrack that was packed down from other Fatbikes and hikers. Super fun, you're basically always in a drift. With <7 psi in the tires it was pretty good traction over bumps and could hold a line through a corner well. Not gonna lie, I laid it down a few times. I actually think this would be a great bike for flat pedals since you're pretty much always in a drift and then it's easy to plant a foot. I also pulled a trailer on a packed/plowed road. It felt under control on even the most slippery sections of road and even in 4" of fresh stuff.

        Hits: Great looks, lightweight, geometry is spot on, excellent build for this price, great finish.

        Misses: Handlebar is narrow. A bike of this prowess deserves a wider stance. Tires had some runout, I know it doesn't affect the ride really but it makes the product feel cheap. I'd have liked slightly lower gearing for deeper snow/slower speeds. Cable actuated brakes, while reasonably priced, had very little modulation and were noisy in the cold.

        Don't pass GO, don't collect $200, go directly to the checkout and cash in on the Fat fun.

        You Need This Bike


        • Familiarity: I've used it once or twice and have initial impressions

        I have been a tyrannical weight weenie for the past 23 years of riding. So the thought of riding a heavy fat tire bike with the handling of a tugboat was not appealing. This thought was in the back of my mind when I checked out a Yampa demo at OuterBike in Moab. The test trail was a mix of hard pack, rock gardens, stretches of sand and tight turns. After a few pedal strokes, the overall lightweight of the Yampa's full carbon frame was noticeable. To my surprise, i wanted to hammer this bike. It was a bit of a revelation, I was passing guys on full suspension bikes without a problem. The last section of trail was made up by a long set of berms. The big tires were able turn into the berms at insane angles and the laterally stiff frame kept the bike on track. After getting a feel for the bike, i felt like a few changes could really personalize things for me. I would like to run the bike with a wide flat 720mm bar and a short 50mm stem. Also, playing with a lower tire pressure would help take the edge off some of the rocky areas of trail. Overall, I really like this bike and I can't wait to give the Yampa a try on some snow.

        Hands down the best fat bike out there

        • Familiarity: I've used it several times

        I've been interested in fat bikes since the Pugsley stormed the market a few years ago. I've ridden the Pugsley, Bear Grease, Mukluk, and various other fat bikes. They all felt sluggish in every condition. Although they provide a really comfortable ride quality, the handling felt more like I was trying to steer the stay puff marshmellow man into a corner, rather than a sweet fat bike. The Borealis Yampa is NOTHING like that. In fact, it is a million times better than that. While riding a Yampa in Southern Utah recently, the first thing I notice about the bike was how responsive it is. I didn't have to jerk the front tire up over obstacles as though I was sailing a yacht. When powering up short steep climbs, I never felt like my power was lost in translation, the bike just zipped up everything. The Yampa is definitely the fat bike I will be buying for all my fat bike adventuress.

        borealis fatbike ...soooooooo gooooooood

          i test this Fat bike at the outerbike was the fastest fat bike that i rode in my life and the most confortable, the chainstay is acting like a suspension and the bike still so stiff for the pedaling efficiency was amazing ....i was so fast then i ask to borealis to got a sponsorship ..and bang i got it ..i am so proud to race with this bike...its a innovation. Thanks Borealis for your help...

          wow-this bike is Fun!

          • Familiarity: I've used it several times

          I had the opportunity to ride this bike at Outerbike in Moab this year and had an absolute blast on it. The bike was so light weight and agile i totally forgot i was riding a rigid fatbike. If you are in the market for something to ride over the winter months in the snow or in the sand this is definitely the fatbike to get!

          wow-this bike is Fun!

          can you add after market front suspension forks?

          That is a great question. Unfortunately, this Yampa frame cannot run a suspension fork .

          If you have any questions if this bike is right for you, I will be happy to help you out. I am usually in the office Monday/Tuesday/Thursday/Friday 11:30am-9:30pm you can request me by phone (1.888.276.7130 ext. 4646) during those hours. You can also send me an email @ at any time.

          Yes you can run a Bluto on it, but you would need 150mm front hubs, the stock 135mm would not work. Also, the Bluto will only work on the L and XL Yampa, and recommended 80mm travel not 100mm. Internet search reveals the above answer straight from Borealis

          Does the black/white Yampa that is currently on sale comes with black or red rims? Thanks!

          Best Answer

          The Black/White bike actually has blue wheels. We have one remaining with black wheels. PLease call me directly @ 801-736-6396 x4378, or e-mail to specify the variant you would like.

          What model year is this bike? Could I mount a RockShox Bluto on it?

          Could you provide more details on the hubs, which model?

          How much assembly is needed?


          If you are planning on ordering one of the Yampa's that are currently on sale, I would strongly suggest that you read my post concerning the Bright Red Rims that they switched to without telling anyone. They still have not updated their website to mention the substitution. So buyer beware.

          Model year 2014, frames produced in 2014 and 2015 though with no change. Not recommended to mount a bluto - will void warranty, and a bluto does not have the correct offset. Borealis brand hubs, 135x15 front, 197x12 rear. Not sure exactly how BC ships these but very minimal assembly should be required on your end - bar install, wheel install, stuff like that.

          Are these 2014 frames and hubsets with exchangeable end cap on the rear hub to change to a thru-axle setup?

          Is the product made ??in the USA? Is the...

          Is the product made ??in the USA?

          Is the product made ??from?

          To answer your question the bike is manufactured in China. Which as you know has become a standard practice in most cases. This is not necessarily a bad thing because there are still very rigid quality assurance practices going on within this company.

          If you need any other information please do not hesitate to give me a call or email me at



          What is the BCD pattern on the crank's...

          What is the BCD pattern on the crank's spider? In some of the photos it's 104, in others it's 94.

          Best Answer


          That photo you are seeing is the Surly OD crankset that Borealis originally spec'd and have made a rolling change to. The crankset spec'd on these bikes currently are the Race Face Ride 22-36 crankset which has a 104 BCD. If you have any additional questions please feel free to contact me at