Borealis Flume Aluminum Fat Tire Bicycle

Borealis Flume: Built for Epic Adventures Conquer mountains, snowfields, deserts, and everything in between on the Borealis Flume. Engineered around a lightweight 6000-series aluminum frame and a Borealis Carbon Rigid Fork, the Flume is designed to tackle any terrain with confidence. Choose between a SRAM NX Eagle or GX Eagle 12-speed drivetrain for precise shifting, while SRAM Level T brakes deliver all-weather stopping power. A carbon handlebar and seatpost keep the weight down without sacrificing strength, and Sun Ringle Mulefüt rims provide the durability you need for rugged rides. With clearance for up to 26x5” or 27.5x4.5” tires and compatibility for 100–120mm of suspension travel, the Flume adapts to your style—whether you’re cruising winter singletrack, bikepacking across deserts, or hauling gear through alpine passes. Add in 2–3 bottle cage mounts, rear rack mounts, and Lizard Skins protectors, and you have a fat bike that’s truly expedition-ready. Contact us today to build yo