When RockShox took the lid off the new Bluto suspension fork, something happened to the world of fat bikes. All of a sudden, the line between super fat all terrain crusher and traditional mountain bike was obscured in the roost of a 4.8″ tire thanks to the availability of a mass produced suspension fork. Not only does the fork expand the abilities of fat bikes as we know it, it also has caused frame manufacturers to alter the geometries of their bikes, building new suspension corrected fat bikes with more traditional mountain bike geometry.
As one of the newer players in the fat bike market, Borealis worked with RockShox thanks to their proximity to introduce the all new Borealis Echo as soon as the Bluto got official. After an impressive showing at Sea Otter, Borealis boxed one up (in two boxes!), and shipped it to us for review.
Put away your preconceptions, and hear what the Echo’s all about, next…
Most likely, the Echo would be nothing if not for the RockShox Bluto suspension fork. Yes, there were fat bike suspension forks before Bluto, but RockShox has the ability to mass produce the forks at a price people can afford. It’s light. It’s simple. And it works. All good things when it comes to a new product. Our only complaint so far with the Bluto is that when running a 4.8 Surly Bud on the front with an 85mm rim in the mud, you are left wanting more tire clearance in the arch. Otherwise the suspension damping was adequate, and after some server thrashing it’s working perfectly.
Our test bike was set up with Borealis’ Carbondale rims laced to their own hubset built to 197×12 rear and 150×15 front to match the Bluto. Like the addition of any carbon wheels to a mountain bike, the wheelset definitely had a huge impact on the ride quality in a good way. Expensive yes, but very impressive. For the hell of it, I took a tire completely off the rim to see how difficult it was to get back on and seated tubeless. Without any loud pops or bangs, the tire gradually slid into place and held firm with an air compressor (a weak one, that is on its last legs). No complaints here.
Continuing the build was a 1x drivetrain mixed with XX1, X01, and RaceFace components. RaceFace 35mm carbon bars and an Atlas stem provided the cockpit in addition to the RockShox Stealth Reverb seat post. Yes, a dropper post on a fat bike. And it’s awesome.
Of course all that awesomeness comes at a price. In this case, the XX1 stock build of the Echo retails for $5999. Add in the price of the dropper post and $1599 for the Carbondale rims, and you have a fat bike north of $7600. Definitely not cheap. Rolling the stock aluminum rims with smaller 4″ Husker Du tires should work out to a similar weight though.
On the scale the complete bike came in at 28.59lbs which is not super light by today’s fat bike standards, until you consider the dropper post, suspension fork, and 4.8″ tires. In case you’re wondering, the fork itself weighs in at 1,820g or 3.99 lbs with a steerer tube cut to fit and the Maxxle installed.

Riding Impressions:
Reactions to the Echo were a peculiar thing. Nearly everywhere it went, reactions were equal parts astonishment thanks to the big tires, and also pity at the fact that it would inevitably be a painfully slow ride. Of course, at each stop along the way the Bluto equipped Echo proceeded to blow everyone away demonstrating that speed and agility aren’t just for regular mountain bikes. Even with the added girth of the tires, the Echo proved to be just as capable as any hard tail I’ve ridden. No, scratch that, the Echo is more capable thanks to the added flotation and insane amounts of grip the big tires provide.
Going into the review there was an upcoming short track race, that even I was a little hesitant to race it on a fat bike. There was a fat bike class though, so I saddled up and actually won. Not just the fat bike class, but I finished well ahead of the entire field. Admittedly, thanks to a monster downpour just before the start of the race, the conditions were favorable for bigger tires (it was the muddiest race I’ve done). Still, none of the spectators or promoters expected a fat bike to cross the line first, and by such a large margin.