Borealis Flume 27+ (Mastadon Fork) Fat Bike
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.
Standard features include: SRAM Eagle NX 12-Speed drivetrain, SRAM Level T brakes, Mastodon Pro Ext. fork, carbon handlebars, carbon seat post, durable 26" Sun Ringle Mulefüt rims and 4.8" Schwalbe Jumbo Jim Tires for max snow flotation.
Frame geometry provides responsive handling, offering maximum control for varying conditions in snow or sand.
Tire clearance up to 26x5” and 27.5x4.5”.
Lightweight, 6000-series aluminum frame comes with 2-3 bottle cage mounts, rear rack mounts on seat stays and Lizard Skin protectors on both the down tube and drive-side chain stay.
|Frame||6061 Aircraft Alloy, 197mm Rear Spacing, Internal Dropper Compatible|
|Fork||Mastodon Pro Ext.|
|Headset||FSA 1 1/8 x 1 1/2"|
|Rims/Wheels||Velocity Dually 27.5 + Double-wall alloy, 39mm internal width/45mm external width|
|Hubs||Borealis Brand 150 x 15mm, 197 x 12mm with Shimano HG Freehub Body|
|Tires||Schwalbe Nobby Nic 27.5 x 3.0", Tubeless Ready|
|Crankset||SRAM DUB NX Eagle, 175mm|
|Chainrings||30 Tooth SRAM Direct Mount|
|Bottom Bracket||SRAM DUB|
|Chain||KMC 12-Speed With Quick Link|
|Rear Derailleur||SRAM NX Eagle 12-Speed|
|Cassette/Rear Cogs||SRAM NX Eagle PG-1230 Eagle, 11-50t For HG Freehub|
|Shifters||SRAM NX Eagle, trigger, 12-speed|
|Handlebars||Borealis Carbon SL Low-Rise|
|Tape/Grips||Borealis Ergonomic Locking|
|Stem||Borealis, Length May Vary|
|Brake Levers||SRAM Level T Hydraulic|
|Brakes||SRAM Level T Hydraulic With 160mm 6-Bolt Rotors F/R|
|Pedals||Basic Plastic Test Pedals|
|Saddle||Borealis With Cut-Out|
|Seat Post||Borealis Carbon Rigid, 31.6mm, Length May Vary|
|Accessories & Extras||Rubberized Chainstay Protector|
* Subject to change without notice.