Skip to product information
1 of 4

Borealis Flume Aluminum Fat Tire Bicycle

Borealis Flume Aluminum Fat Tire Bicycle

Regular price $ 2,299.99 USD
Regular price Sale price $ 2,299.99 USD
Sale Sold out
Shipping calculated at checkout.
Drivetrain Kit

The Borealis Flume is an expedition-ready fat bike that is built to handle any adventure. With a lightweight 6000-series aluminum frame, it features a SRAM Eagle NX 12-Speed drivetrain, SRAM Level T brakes, and carbon handlebars and seat post. The durable Sun Ringle Mulefüt rims and your choice of tires provide maximum control and responsiveness, even in the toughest conditions. With clearance for tires up to 26x5” and 27.5x4.5”, and compatibility with 100-120mm of suspension travel, this fat bike is perfect for tackling mountains, glaciers, and deserts. With 2-3 bottle cage mounts, rear rack mounts, and Lizard Skin protectors, it's also equipped with all the extras you need for your next adventure. Contact us today to build your custom Flume!



Eagle 12 speed Flume Specs (1×12)

Eagle NX Eagle GX
Crankset SRAM Eagle NX SRAM Eagle GX
Crank Arms 175mm Alloy 175 Alloy
Rear Derailleur RD ENX 1 x 12 RD EGX 1 x 12
Chain KMC X12 KMC X12
Cassette PG 1230 11-50 XG 1275 10-50
Shifters SRAM Eagle NX SRAM Eagle GX
Brakes SRAM - Select SRAM - Select
Chain Ring SRAM 30T X-Sync
Frame Borealis Crestone Carbon
Fork Borealis Carbon Rigid Fork
Headset Borealis
Hubs Borealis: Front 15×150 Rear 12×197
Rims 26" or 27.5" Sun Ringle Mulefut V2
Spokes Borealis Straight Gauge
Nipples Borealis Silver Brass
Tires Your Choice
Bar Borealis Carbon Bar (35mm)
Stem Borealis 50mm or 70mm
Post Borealis Carbon Seatpost (31.6mm)
Saddle Borealis
Grips Borealis
Bottom Bracket SRAM DUB 100mm
DT/CS Protector Lizard Skins
Weight See weight calculator for exact weight.

EFFECTIVE TOP TUBE 23.02 in 24.02 in 24.8 in 25.59 in 585 mm 610 mm 630 mm 650 mm
SEAT TUBE CENTER TO TOP 15 in 17.01 in 19.06 in 21.02 in 381 mm 432 mm 484 mm 534 mm
HEAD TUBE 4.13 in 4.72 in 5.31 in 5.91 in 105 mm 120 mm 135 mm 150 mm
SEAT TUBE ANGLE 73 deg 73 deg 73 deg 73 deg 73 deg 73 deg 73 deg 73 deg
HEAD TUBE ANGLE 70 deg 70 deg 70 deg 70 deg 70 deg 70 deg 70 deg 70 deg
STANDOVER HEIGHT Due to various rim and tire options stand over is not identified.
CHAINSTAY 17.91 in 17.91 in 17.91 in 17.91 in 455 mm 455 mm 455 mm 455 mm
BB DROP 2.36 in 2.36 in 2.36 in 2.36 in 60 mm 60 mm 60 mm 60 mm
REACH 16.04 in 16.65 in 17.22 in 17.76 in 407.3 mm 423 mm 437.5 mm 451.2 mm
STACK 23.50 in 24.05 in 24.61 in 25.16 in 597 mm 610.9 mm 625 mm 639.1 mm
What Size? Shipping FAQ View full details