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An In-Depth Review: The Borealis Yampa Fat Bike

According to the Oxford English Dictionary, the adjective form of “fat” is defined as “(of a person or animal) having a large amount of excess flesh”—not quite a fitting description for a bike. In my experience, referring to something as “fat” has always been less than flattering, even if the “f” is dropped in favor of a “ph” for a positive affirmation.

However, I’ve never been a fan of pigeonholing, either, which is what the term “snow bike” truly does. The Borealis Yampa is far more than that, and as my time with the Yampa has proved, powder conditions are an unconquerable force of nature anyway. Yes, you can ride the Yampa in some snow, but the smiles really begin when the Yampa is in the dirt. Ultimately, though, where the Yampa succeeds is where other fat bikes fail: melding the distinct sets of geometry and weight requirements for both dirt and snow into one seamless package. The result? One bike that fits the bill for multiple usages.

First Impressions

Looks are indeed deceiving when it comes to the Yampa—this damn thing is light. I was set up on a medium X0/X9 build, and with pedals, it only tipped the scales under 29lb. The geometry is duty-driven, with a 69.8-degree head tube angle that sort of plays in the middle of the field. It’s steep enough for hard drives, but slack enough to really lay it into corners. For reference, the Santa Cruz Bronson features a 67-degree head tube, while the Orbea Alma rests at 71.5 degrees. This puts the Yampa sort of in between XC and trail. However, where the feel really changes, and this is due in part to having to accommodate massive tires, is in the nearly inch-longer chainstays and the substantially taller head tube.


Aesthetically, the Yampa looks tough, so be prepared to field questions and to deal with gawking and glares. And in terms of fit, namely stack and reach, I found it to be pretty predictable. One of the biggest highlights, though, is its dare-to-dream level of accouterments. Yes, I’m referring to rack mounts and the adventures that they hold.

The Ride

To get it out of the way, just because you have a fat bike doesn’t mean that a pow day is now a play day. Six inches of powder is going to make climbing and descending a frustrating, if not impossible, affair. If you insist on riding in the snow, find some trails that are pretty well packed-in from walkers, snowmobiles, or Nordic skiing. With a loose inch or two on the ground, the Yampa experience is as easy as riding a normal bike. In other words, the Yampa climbs as well as any other 27lb hardtail out there—not amazing, but not terrible. To ensure this, though, I recommend playing with the tire pressure—I found the sweet spot to be around 8PSI.


When the trail turns downward, the Yampa is more than competent. I wouldn’t go as far as to say that it’s comparatively snappy and agile as to something like the 5010, but its large tires, geometry, and carbon layup aren’t as brutalizing as your typical fully-rigid experience either. Trail conditions permitting, the light front end of the Yampa allows you to be pretty precise in your line selection, while the 2.1-inch bottom bracket drop creates a confident center of gravity and position over the bike. What I’m getting at is that it’s a really fun descender, especially with flat pedals. Basically, if you’re willing to adapt your descending style to embracing the fat tires, you’ll be surprised at what you can get away with—think mow over everything in sight.


The real drawbacks of the Yampa are mental preconceptions; that and it’s fully rigid. On the former, though, adopting a narrow view of it as a snow bike takes away from its real power. Yes, you can ride in the snow, but if your local trail system turns into a sandpit by June, the Yampa will take it in stride. If you want to bike-pack for a weekend, the Yampa is willing and able. Boiling down what’s actually fun about mountain biking to its essence is what makes the Yampa particularly awesome—it answers to adventure.


The Takeaway

It’s an all-around fun bike, and it has the potential to be a three-bike-quiver in one machine. The low weight eliminates the penalties that typically come with fat bikes, and the carbon construction responsible for this also responds equally well on the way up as it does on the way down. If you’re able to dismiss the notion of a fat bike as a novelty item, which you should, there’s really nothing else like the Yampa on the market.


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Borealis Bikes Yampa XX1 Complete Bike
Borealis Bikes Yampa X0/X9 Complete Bike