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Borealis Fat Bikes Flume GX Rigid Fork

Borealis Fat Bikes Flume GX Rigid Fork
  • Color: Blue and White
  • Color: Blue and White
  • Color: Blue and White
  • Color: Blue and White
Blue and White
Please select options
NOTE: "In store" availability on bicycles includes bikes fully built and bikes still in boxes. Please contact us via the live chat icon at the bottom of the page or call us at (303)444-4196 to confirm build status. ----------------This item is not permitted to be shipped, however it can be purchased online and picked up at your convenience. We are currently also offering City of Boulder Home Delivery for $10 on any purchase under $100 and free for anything over.

To use our $10 Local Delivery service, select it while viewing your cart or during the checkout process.
Please call us at 303-444-4196 with any compatibility questions! We are always happy to help.


With premium frame quality and only the best components, the Borealis Flume offers the best 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.


-Traditional fat bike geometry is both responsive and nimble for variable conditions in snow or sand.
-Standard features include: Eagle GX 12-Speed drivetrain, rigid alloy 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.


Frame Borealis Alloy
Fork Borealis Rigid Fork
Headset Borealis
Rims/Wheels HED Alloy 27.5" x 80mm, or 26" HED Alloy
Hubs Borealis: Front 15×150 Rear 12×197
Spokes Wheelsmith Black
Tires Maxxis Colossus 27.5 x 4.5, or 26"
Crankset SRAM Eagle GX, Arms: 175 Alloy
Chainwheel 30 Tooth
Bottom Bracket SRAM DUB 100mm
Chain KMC X12
Rear Derailleur RD EGX 1 x 12
Shifters SRAM EGX
Handlebars Borealis Carbon Bar (35mm)
Tape/Grips Ergon GA30 or Ergon GP 10L
Stem Borealis 50mm or 70mm
Brakes SRAM - Select
Saddle Borealis
Seat Post Borealis Carbon Seatpost (31.6mm)
Accessories & Extras DT/CS Protector: Lizard Skins

* Subject to change without notice.

Part Numbers

Option MPN Store SKU
Blue and White / Medium / 26" 24923 210000024923
Blue and White / Medium / 27.5" 21417 210000021417