The Keystone is my first e-bike having been a fat tire mtb enthusiast this was a no brainer, it is the most fun I’ve had on a fat tire bike. Love it !! thanks Borealis.

Bought this xl frame to replace my 5 year old crestone. There was nothing wrong with my old one (had 13,000 + miles on it) but the blowout price on the xl was so good i had to buy it. paint is incredible.

This is my third eFat and although I liked other two - the Keystone is just beyond. I set mine up with a Redshift ShockStop seatpost (hardtail with benefits!), Ergotec 45 degree by 50 stem, carbon riser bar, and Schwalbe Al Mighty 4.8 tires (328 Billy Flamingo studs per baby!) The T-type drivetrain blew me away so much I converted my other bikes.

I also received unbelievable service from the Borealis sales rep during purchase.

Simply heaven!

They are great for Mountain Biking!!

Completely happy with this fat bike purchase. Extends my ability to ride during winter months here in Park City Utah

Wheels and hubs are great!

I finally have a day here where I could use these new rims. I put 3” slick tires on these rims and use them for paved trail riding. The hubs are very quiet compared to the Novatec hubs I use out on trails. They fit a Surly Wednesday perfectly. Thank you for the great price and quality wheels.

I have the carbon version and wanted a second set. Very good quality for the money . Easily setup for tubeless.

What a beautiful and well built frame! Great pricing deal and customer service was top notch.

Love the bike. I have had brands of fat bikes and the flume performs the best. The aluminum frame had super clean welds and the paint has a high quality finish. The weight was several pounds lighter than bikes at the same price point Overall impressed with ride and quality

My Crestone frame shipped very quickly via FedEx and arrived in perfect condition. It’s beautifully and looks incredibly sturdy. Bike is now built up and ready to ride. I want it to snow!

I’ve never written a review before, but lets give this a shot.

My journey started with a my buddy buying an analog fatty and encouraging me into following him. I’m 63 years old, live at 8,400ft elevation in Eastern Sierra, been riding eMTN bike several times a week for just over a year, and it seams like everything I ride is uphill. I tried my buddy’s bike and I could not climb my normal route (1,000ft/7miles). I began researching fatty eMTN bike and quickly found Borealis Keystone. I lamented for several weeks and pulled the trigger early November 2024.

I had questions on choosing the right tires/wheels. The staff was very helpful discussing my riding style/needs and helping me select the right combination (26”, 4.8”).

The bike arrived 3 weeks later (delayed at my request d/t travel). It was meticulously packed and I assembled it on my workbench/clamp. It took about 4 hours (I’m kind of slow and it was the first time. I had not changed my own tire in 50 years). I called the shop for assistance in assembling/sequencing the rings at the head tube. They were quite helpful and got me back on track. I was surprised to learn the bike did not include pedals and it took me several days to acquire some. [Recommendation to Borealis, give options to choose pedals/opt out during the purchase process, just like tires and wheels].

This bike has exceeded every expectation. It handles soundly. Shifting and breaking were flawless without any user adjustments. I can travel uphill/downhill with confidence.

Regarding the battery/range. My ride last week (1hr:43min, 2,746ft elevation gain, and 14 miles) left me using 40% of the battery. I failed to charge that night. I followed this with a longer/steeper ride/climb (3 hrs, 3,865ft, 25 miles) and ran my battery dry in the last 1/2 mile. I mostly ride in ECO mode and occasionally use TRAIL and seldom use BOOST. I can conclude that if you need more than 5 hrs and 6,600 elevation gain, and 40 miles, on 3-5 psi, then you might consider carrying an additional battery.

Regarding versatility, during these two rides above, I traveled on snow, ice, sand, rock garden, slush, hard pack road base, gravel, asphalt, and 12” deep creek. During these two rides, I only lost control when crossing the creek and found an unexpectedly deep rut. This caused me to step off my bike. On other rides, I went down when hitting ice as I did not opt to put studs in the tires (live and learn).

There is truly no terrain this bike cannot handle (however, I recommend considering studs for ice, I have not tried this option).

Today, I noticed my rear brake was soft and the lever pulled back to the bar. I had to stop my ride. I’ll take it locally for a bleed tomorrow morning and hope to ride in the afternoon.

If you want to HAVE A BLAST on the mountain or just want to expand your riding season to 12 months a year, this bike is for you!

I received my new Flume in two boxes and packaged well. Assembly and adjustment were easy and there is also a video to guide you through the process. After riding it for the first couple of miles in the snow I knew that I made the right choice by going with BOREALIS.

The customer service closed the deal for me. They answered all my questions in detail and responded to emails within 24 hours. Bike packaging and assembly were pain free. Make sure you follow the assembly video. I am 100% satisfied which is rare since I’ve owned and rode many bikes over the years Thank you.

Great carbon bike for this price point