While on the surface this is a straight forward bike review, it’s impossible not to also delve into the question of whether fat biking is truly viable segment of the mountain bike world. Until taking delivery of the Borealis Echo test bike, I had all of two fat bike rides on my career cycling resume. I loved them both, but it wasn’t entirely evident at the time what a beast this whole big wheeled business was going to become. It still had that niche-of-niche feel.

Flash forward to the present, and it’s clear at least from an industry standpoint that fat biking is not just a pastime for snowbound Minnesotans. Many of the big boy manufacturers got into the game this past year, and we fully expect that trend to continue with more fat bikes and fat bike specific components streaming into the marketplace in 2015 and beyond.

But does that mean you should run out and buy one? My answer, after spending about two months tooling around on the Borealis Echo, is I certainly want one. They’re truly a ton of fun — and based on my test time, not limited to bombing around in blizzards. I’m no Gee Atherton (or even Rachel Atherton), but I can go downhill okay on my 160mm-travel trail bike. Yet I managed to PR a couple descents on the Echo, which is testament both to the bike’s nimble handling (yes, I said nimble), and the ridiculous amount of traction delivered by 4.8” tires pumped to 9 psi. It almost feels like cheating.

Of course, at $5,100 the Echo is also draped with lots of high-zoot parts (and a few not-so-hot ones), which you can read about in the full review below. But before you do that, check out this video from the folks at Borealis. If you thought fat bikes were only for snow and sand, they encourage you to think again.

Tire clearance: Up to 4.8” on 100mm rim Wheels: Turnagain FR80 Drivetrain: SRAM X01 1×11 Hubs: Borealis FH150 Cranks: RaceFace Turbine 32t Bottom Bracket: Threaded 100mm shell Suspension: RockShox Bluto RL 100mm Tires: Surly Bud/Lou 4.8 120tpi Brakes: SRAM Guide RS hydraulic Routing: Internal cables/internal dropper post Bars: RaceFace Turbine 35mm Cargo: Three bottle cage mounts Stem: RaceFace Atlas Weight: 31 pounds (size L as tested) Headtube: 1 1/8-to-1½ tapered MSRP: $5,100 (stock XO1 build) Seatpost: RaceFace Turbine Rating: 4 Chilies-out-of-5 Saddle: Ergon SME30 Pro

Huge smile factor Heavy wheels Lightweight frame Heavy tires Nimble handling (seriously) Heavy tubes Great brakes Not tubeless Reliable 1x shifting Auto-steer at lower pressure Reliable chain retention Bombproof cockpit Massive tire clearance Short chainstays Convertible to 29+ All season versatility Traction, traction, traction Stability at speed Fully guided internal routing Stiff efficient frame Climbs like panzer tank Smoothes out trail chatter Internal dropper post compatible

As anyone who’s spent time in the Boulder, Colorado area knows, it’s a wonderful place — unless you like doing quality mountain bike rides out your front door. Indeed, though the area is blessed with hundreds of acres of scenic public open space, most of it is off-limits to bikes. In the battle for trail access, the angry hikers won.

The trails that do allow bikes are mostly family-friendly fare, posing little challenge for anything beyond a hardtail (or even a ’cross bike). But what they do provide is a test lab for human interaction. Boulder’s trails are busy, which often means the old stink-eye showdown between walkers and riders. Funny thing, though. When out on a fat bike, those frowns turn upside down. Apparently people love fat things, even though I could go just as fast or faster on the Echo compared to my other bikes, and if we did get tangled up in a blind corner, this 31-pound rig of rolling thunder would do a heck of a lot more damage than my 16-pound ’crosser.

That brings us to the Echo itself, which Borealis claims to be the first fat bike designed specifically around the RockShox Bluto, a 100mm fork that first came to life just a few miles from Borealis HQ in Colorado Springs.

“Honestly we probably didn’t any more advantage than any of the other manufacturers, but [RockShox engineers] did come to our office a lot and, say ‘let’s ride,’” explained Borealis CEO Steve Kaczmarek. “Our buildings are maybe four miles apart. That’s why we are almost exclusive on SRAM.”