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Fatbiking adventurers know that inspiration matters, and a ride (or bike) is only as good as the idea that created it. The expedition-ready Flume capitalizes on all the sweetness of the Crestone, 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. The custom tubeset mates ideal, high-performance geometry with competition-ready spec. But if pedaling across our blue planet is more your speed, the Flume will speed you through.
The Flume is built on an alloy frame that draws on all of our experience in making fat bikes at a much lower price.
- All aluminum frame with careful attention to finish details
- Borealis unique geometry for the best ride experience
- SRAM GX components
- Available in two colorways
- Reduced stand over height
- Carbon bar & seatpost
- Carbon fork
GX Flume Specs (1×11)
|Frame||Borealis Flume Lightweight 6066 Alloy Frame (Orange/Black/Green)|
|Fork||Borealis Carbon Rigid Fork or Bluto RL|
|Hubs||Borealis. Front 15×150 Rear 12×197 Black|
|Nipples||Wheelsmith Silver Brass|
|Bar||Borealis Carbon 35mm|
|Stem||Borealis 50mm/70mm for XL|
|Post||Borealis Carbon 31.6mm|
|Crankset||SRAM GX Alloy w/30T Chain Ring|
|Rear Derailleur||SRAM GX 1×11|
|Cassette||SRAM XG-1150 10-42|
|Shifters||SRAM GX 1×11|
|Brakes||SRAM Level T w/Centerline 160/160mm rotors|
|DT/CS Protector||Lizard Skins|
|Weight||~26lbs 15oz +2lbs for Bluto|
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.
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
|Effective Top Tube||23.78 in||24.02 in||24.8 in||25.59 in||604 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|