Borealis Keystone Review | Where Can’t It Go?

The one thing I don’t enjoy about some other fat tire bikes is often the marketing language. They’re often portrayed as a go-anywhere-and-do-anything e-bike. The problem with that is most fat tire bikes are designed as hybrids meant to be comfortable to commute on while being able to not fall apart if they hit a multi-use dirt path.

The Keystone is a different breed. You can enjoy riding on any good hardtail-friendly MTB trail with versatility beyond that that. Think OHV areas, gravely, sandy stuff. Situations where you need a tire to float, not shred.

Borealis lets you pick your tire and wheel size. With mountains of sand here in our local Southern Utah desert, we opted for the widest Terrene Johnny 5 tires and thoroughly enjoyed riding over sandy trails.

The parts picked for the rest of the bike are a cut above most in the fat bike world.

The Manitou Mastadon fork is a special fat tire fork optimized for extreme conditions and use. The 120mm of travel is plenty since the tire volume further softens the ride. You won’t be doing intense downhill on this setup, but if you want enhanced comfort on something that can tackle diverse terrain, it more than checks that box.

The SRAM G2 brakes had great stopping ability and gave us a controlled ride.

The electronic shifting of the SRAM AXS system isn’t necessary for having a fun experience, but it’s undeniably cool and something many mountain bikers will envy. As a bonus, you can shift with abandon on the trails; it’ll guide you through shifting under load to help best preserve your drivetrain.

Overall, the Keystone was a playful adventure bike. It was fun to romp around on, and it handles well in different settings. There was a lot of evidence that it was made by people who know a thing or two about fat bikes.

There wasn’t much to criticize except maybe the lack of accessories available to pair with the bike at purchase. That’s about as first-world as problems get, though, and you can find what you need to add for overlanding, hunting, or other adventures elsewhere online.