The Borealis Flume offers the best fat bike value on the market. This expedition-ready fatty mirrors the Crestone geometry, but does so in lightweight, 6000-series aluminum. Up mountains, down glaciers, and across deserts - the Flume is ready for action. There are all kinds of alloy fat bikes on the market, but none with the Flume’s purebred heritage and durability.

HIGHLIGHTS

• Traditional fat bike geometry is both responsive and nimble for variable conditions in snow or sand.
• Standard features include: Eagle NX 12-Speed drivetrain, rigid carbon fork, carbon handlebars, carbon seat post and durable Sun-Ringle Mulefut rims.
• Tire clearance up to 26x5” and 27.5x4.5”.
• Compatibility for 100-120mm of suspension travel for increased comfort and control.
• Lightweight, 6000-series aluminum frame comes with 3 bottle cage mounts, rear rack mounts on seat stays and Lizard Skin protectors on both the down tube and drive-side chain stay.
• Available in two colorways
• Reduced stand over height

SPECS

• Chainstay and seatstay protectors
• Seatpost collar
• Rear axle and derailleur hanger

Frameset includes all of the above as well as:

• Complete headset and compression plug/ star nut
• Front axle
• Fork of your choice

All frames are covered by a 5 year warranty and crash replacement program.

RIDER HEIGHT RECOMMENDATIONS
Based on our research, riders at the heights below will usually take the corresponding frame size. If you’re at a transitional height that spans two sizes, look at the geometry chart to get the Stack and Reach you like based on other bikes you are comfortable.

GEOMETRY & SIZING
Borealis offers four frame designs with unique fit and geometry to suit your every Fat Bike need. Begin by taking a rough size approximation on the chart below that is based on height, then select the corresponding bike with your fit needs by using the geometry chart further below. We recommend a similar fit to you mountain bike, so grab a measuring tape and dial it in.