The fatbike to rule all fatbikes.

When we saw that the components for a new kind of bike – the fatbike – were becoming more widely available, we saw huge opportunities to extend our riding throughout the year. Many others saw the same opportunity, and a true community has sprung up around winter riding. Maybe it’s seeing your trails in a totally different way (and often at night). Maybe that post-ride beer tastes that much better when it’s a heavy winter warmer and you’re out playing in the snow. Maybe it’s because you’re always wrecking and there just aren’t many consequences when falling into deep snow. Whatever it may be, you’re sure to have a good time if you’re out riding a fatty.

Whatever the reason, we build these bikes to go fast. Scoff if you want; they rip! We take the same design philosophy we use on our trail bikes and give it some tweaks here and there to tune the bike to ride just right with those big tires.  Pinion and Rohloff internal gearing systems are available as options if you want the utmost in reliability and gear range


  • Steel or Titanium construction
  • 44mm ID head tube, compatible with 1-1/8” straight or 1.5″ tapered steerers
  • 12x177mm Rear through axle, 12x197mm available as a custom request
  • Tire clearance:
    • 177mm: Surly Nate 4” (geared drivetrain) Surly Lou 4.8” (single speed only)
    • Clearance for VeeRubber Snowshoe 2XL 5.1″ tire is available with a our custom 197mm rear spaced bike, Email for details!
  • 100mm English (BSA) threaded Bottom Bracket shell
  • Paragon Machine Works sliding dropouts with replaceable/customizable inserts (run it SS or geared)
  • 31.6mm ø seat post
  • Designed around the RockShox Bluto, 120mm
  • Custom Powder Coat colors available at $250 upcharge
  • Pinion Gearbox, Rohloff, and other custom options available.  Email for details!
FRAMEVari-Wall THERMLX, Air Hardening, Seamless, Heat Treated Steel, Handwelded in USAVari-Wall THERMLX, Air Hardening, Seamless, Heat Treated Steel, Handwelded in USA
FORKRockshox Bluto RCT3, 120mm travelRockshox Bluto RCT3, 120mm travel
HEADSETCane Creek 40Cane Creek Hellbender 70
HEADSET SPACERSAlloy - BlackAlloy - Black
STEMSpank Spoon, 40mmI9 A35
HANDLEBARSpank Spoon RiserRaceFace Atlas 35 Riser
GRIPSSpank Spoon Lock-OnRaceFace Half Nelson Lock-On
BRAKESShimano M7100 SLX discShimano M8100 XT disc
ROTORSShimano RT66 180mm F / 160mm RShimano RT66 IceTech 180mm F / 160mm R
SEATPOSTKS Lev Si DropperKS Lev Si Dropper
SADDLEWTB RocketChromag Trailmaster
WHEELSETSurly My Other Brother Darryl, DT Swiss Comp spokes (handbuilt by REEB)Surly My Other Brother Darryl, DT Swiss Comp spokes (handbuilt by REEB)
HUBSHope Pro4 FatsnoIndustry Nine Hydra Fat
TIRESSurly Bud (front), Surly Nate (rear) 120tpiSurly Bud (front), Surly Nate (rear) 120tpi
RIM STRIPSurly TubelessSurly Tubeless
REAR AXLE12x177mm12x177mm
CASSETTESRAM NX Eagle, PG-1230 11-50, 12 spdSRAM GX Eagle, XG-1275, 10-50 12-spd
DERAILLEURSRAM NX Eagle, 12 spdSRAM GX Eagle, 12 spd
CHAINRINGSRAM 30t X-Sync 2 Direct Mount, SteelSRAM 30t X-Sync 2 Direct Mount, Steel
SHIFTERSRAM NX Eagle Trigger, 12 spdSRAM GX Eagle Trigger, 12 spd
CHAINSRAM NX Eagle, 12 spdSRAM GX Eagle, 12 spd

Generic Geometry Chart


 SmallMediumLargeExtra Large
A. SEAT TUBE14.4"16.3"17.7"19"
B. EFFECTIVE TOP TUBE22.5"23.5"24.5"25.5"
C. REACH15.6"16.3"16.9"17.6"
D. STACK23.3"23.6"24.1"24.5"
E. SEAT TUBE ANGLE73.5°73.0°72.5°72°
F. HEAD TUBE ANGLE66.0°66.0°66.0°66.0°
G. CHAIN STAY18.3"18.3"18.3"18.3"
H. HEAD TUBE4.1"4.5"5.1"5.5"
I. AXLE TO CROWN531mm531mm531mm531mm
J. OFFSET51mm51mm51mm51mm
K. WHEELBASE43.5"43.8"44.6"45.4"
L. BB DROP2.3"2.3"2.3"2.3"
M. STANDOVER29.8"31.1"32.0"32.7"