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 your custom Borealis Flume! Our 2025 Season pricing is now available, offering some of the best deals on the Borealis lineup. Specifications Drivetrain Eagle NX: SRAM Eagle NX Crankset (175mm Alloy Arms) RD ENX 1x12 Rear Derailleur KMC X12 Chain PG 1230 11-50 Cassette SRAM Eagle NX Shifters Eagle GX: SRAM Eagle GX Crankset (175mm Alloy Arms) RD EGX 1x12 Rear Derailleur KMC X12 Chain XG 1275 10-50 Cassette SRAM Eagle GX Shifters Chainring: SRAM 30T X-Sync Brakes: SRAM Level T Frame & Fork Frame: Borealis Flume 6000-Series Aluminum Fork: Borealis Carbon Rigid Fork Wheels Hubs: Borealis (Front 15×150, Rear 12×197) Rims: Sun Ringle Mulefut V2 (26" or 27.5") Spokes: Borealis Straight Gauge Nipples: Borealis Silver Brass Tires: Your Choice Cockpit Handlebar: Borealis Carbon Bar (35mm) Stem: Borealis 50mm or 70mm Seatpost: Borealis Carbon Seatpost (31.6mm) Saddle: Borealis Grips: Borealis Additional Features DT/CS Protector: Lizard Skins Mounts: 2–3 Bottle Cage Mounts, Rear Rack Mounts