Fat Bikes

Since 2013, Borealis has specialized in lightweight carbon fiber fat bikes. The Crestone is our tried and true flagship model. Its frame geometry is optimized for riding in snow and sand with clearance for up to 5” wide tires. Paired with the most technically advanced components in the industry, the Crestone sets the standard for premium quality carbon fiber fat bikes. HIGHLIGHTS: Standard features include: SRAM Eagle NX 12-Speed drivetrain, SRAM Level T brakes, rigid carbon fork, carbon handlebars, carbon seat post, durable Sun Ringle Mulefüt rims and your choice of tires. Frame geometry provides responsive handling, offering maximum control for varying conditions in snow or sand. Tire clearance up to 26x5” and 27.5x4.5”. Compatibility for 100-120mm of suspension travel for more technical riding. Lightweight, durable carbon fiber frame comes with internally routed cables, 2-3 bottle cage mounts and lizard skin protectors on both the down tube and drive-side chain stay. COMPATIBILITY: Rockshox Bluto Fork tire size limitations: 26x5” or 27.5x4” Mastodon Pro EXT Fork tire size limitations: 26x5” or 27.5x4.5” Borealis Rigid Carbon Fork tire size limitations: 26x5” or 27.5x4.5” Dually 29x45 and 27.5x45 Rims – Max tire width: 3” All rims 65mm to 85mm wide are compatible with tire widths of 3.8” to 5” HED Carbon 100mm Rims – Max tire width of 4.6”

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. HIGHLIGHTS 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.

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. HIGHLIGHTS Standard features include: SRAM Eagle NX 12-Speed drivetrain, SRAM Level T brakes, rigid carbon 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.

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. HIGHLIGHTS Standard features include: SRAM Eagle NX 12-Speed drivetrain, SRAM Level T brakes, rigid carbon fork, carbon handlebars, carbon seat post, durable Sun Ringle Mulefüt rims and your choice of tires. Frame geometry provides responsive handling, offering maximum control for varying conditions in snow or sand. 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 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. COMPATIBILITY Rockshox Bluto Fork tire size limitations: 26x5” or 27.5x4” Mastodon Pro EXT Fork tire size limitations: 26x5” or 27.5x4.5” Borealis Rigid Carbon Fork tire size limitations: 26x5” or 27.5x4.5” Dually 29x45 and 27.5x45 Rims – Max tire width: 3” All rims 65mm to 85mm wide are compatible with tire widths of 3.8” to 5” HED Carbon 100mm Rims – Max tire width of 4.8”

Have it both ways! Our Borealis Flume bikes come dirt-ready with 27.5 X 3" plus tires and Bluto suspension forks. As a bonus, these are fully fat-compatible and ready for winter with the addition of a fatbike wheelset. With premium frame quality and only the best components, the Borealis Flume offers the best value on the market. This expedition-ready MTB 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 bikes on the market, but none with Flume’s purebred heritage and durability. HIGHLIGHTS Traditional fatbike bike geometry is both responsive and nimble for variable conditions in snow or sand. Standard features include Eagle NX 12-Speed drivetrain, Rock Shox Bluto Fat Bike Fork. carbon handlebars, carbon seat post and durable Velocity 27.5 rims with dirt-gripping Schwalbe Nobby Nic 3" tires. New Moon offers HED alloy and carbon fatbike wheelsets to upgrade a summer-ready Flume demo starting around $1700. Contact us for more info.

Have it both ways! Our Borealis Flume summer demo bikes come dirt-ready with 27.5 X 3" plus tires and Bluto suspension forks. As a bonus, these are fully fat-compatible and ready for winter with the addition of a fatbike wheelset. With premium frame quality and only the best components, the Borealis Flume offers the best value on the market. This expedition-ready MTB 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 bikes on the market, but none with Flume’s purebred heritage and durability. HIGHLIGHTS Traditional fat bike bike geometry is both responsive and nimble for variable conditions in snow or sand. Standard features include Eagle NX 12-Speed drivetrain, Rock Shox Bluto Fat Bike Fork. carbon handlebars, carbon seat post and durable Velocity 27.5 rims with dirt-gripping Schwalbe Nobby Nic 3" tires. Note: these demos DO NOT include snow-ready wheels and tires. New Moon offers HED alloy and carbon fat bike wheelsets to upgrade a summer-ready Flume demo starting around $1700. Contact us for more info.

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 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 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 chainstay.