The Borealis Flume offers the best fat bike 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.
Frameset includes all of the above as well as:
All frames are covered by a 5 year warranty and crash replacement program.
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.
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.
|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|