Embarking on a new cycling adventure in my sixties, I found myself drawn to the world of fat bikes, or as some call them, Thick Bikes. Living at a high elevation of 8,400ft in the Eastern Sierra and primarily tackling uphill trails on my eMTB, I was intrigued by a friend’s analog fat bike. However, my initial test ride on his bike revealed a struggle to conquer my usual 1,000ft climb over 7 miles. This sparked my quest for a thick tire eMTB, leading me to the Borealis Keystone. After weeks of deliberation, I made the purchase in early November 2024.
Choosing the right tires and wheels for a thick bike can be daunting. Thankfully, the Borealis staff provided exceptional guidance, discussing my riding style and needs to help me land on the perfect 26” wheelset with 4.8” tires. Three weeks later, my meticulously packaged bike arrived (delayed at my request due to travel). Assembling it in my workshop took around four hours – a testament to my deliberate pace and long hiatus from bike mechanics. I did reach out to the shop for clarification on the head tube ring sequence, and their prompt assistance quickly got me back on track. One surprise was discovering that pedals were not included; offering pedal options during purchase, similar to tires and wheels, would be a beneficial addition for Borealis.
From the first ride, this thick tire bike has surpassed all expectations. The handling is remarkably stable, and the shifting and braking have been flawless, requiring no adjustments. Whether ascending or descending, the bike instills confidence across diverse terrains.
Battery range is a crucial factor for e-bikes. My first significant ride (1 hour 43 minutes, 2,746ft elevation gain, 14 miles) consumed only 40% of the battery. Neglecting to charge that night, I embarked on an even more demanding ride the next day – 3 hours, 3,865ft elevation gain, and 25 miles. The battery lasted until the final half mile, running dry just before the finish. Primarily using ECO mode with occasional shifts to TRAIL and infrequent BOOST, I estimate that riders requiring more than 5 hours, 6,600ft of elevation gain, or 40 miles on 3-5 PSI might consider carrying a spare battery.
The versatility of this thick tire e-bike is truly astounding. Over these initial rides, I encountered snow, ice, sand, rock gardens, slush, hardpack, gravel, asphalt, and even a 12” deep creek. The only instance of losing control was in the creek, where an unexpected rut led to me stepping off. I did experience a fall on ice during another ride due to not using studded tires – a lesson learned. This fat bike truly seems capable of handling any terrain. While I haven’t yet tried studded tires, they are definitely recommended for icy conditions.
Recently, I noticed a soft rear brake lever that pulled all the way to the handlebar, forcing me to cut a ride short. A brake bleed at my local shop resolved the issue the next morning, and I was back on the trails that afternoon.
If you’re seeking exhilarating mountain adventures or a way to extend your riding season to year-round, a thick tire bike like the Borealis Keystone is an outstanding choice. It’s a blast on the mountain and opens up a world of riding possibilities, regardless of the conditions.
