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. With the choice of two different rear dropout widths, you can choose whether you want to build a speedy packed snow trail demon or an über-floaty expedition rig. 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
  • 170mm and 190mm rear axle width options
  • Tire clearance:
    • 170mm: Surly Nate 4” (geared drivetrain) Surly Lou 4.8” (single speed only)
    • 190mm: Vee Rubber Snowshoe 2XL 5”
  • BB shell:
    • 170mm: 100mm English (BSA)
    • 190mm: 120mm English (BSA)
  • Paragon Machine Works sliding dropouts with replaceable/customizable inserts (run it SS or geared)
  • 31.6mm ø seat post
  • Designed around the MRP Fat Fork (468mm or 490mm A-C), compatible with the RockShox Bluto
  • Custom Powder Coat colors available at $250 upcharge
  • Pinion Gearbox, Rohloff, and other custom options available.  Email for details!
 PFP 170mmSFP 170mmSFP 190mm
FORKSurly Ice Cream Truck, 15x150mmMRP New Carbon Fat ForkMRP New Carbon Fat Fork
HEADSETCane Creek 40Cane Creek 40Cane Creek 40
HEADSET SPACERSAlloy - BlackAlloy - BlackAlloy - Black
STEMRaceFace AeffectLoaded Components AmXC (color choice)Loaded Components AmXC (color choice)
HANDLEBARRaceFace Aeffect RiserLoaded Components AmXC (color choice)Loaded Components AmXC (color choice)
GRIPSLoaded Components Pistol GripsLoaded Components Pistol GripsLoaded Components Pistol Grips
BRAKESShimano M7000 SLX discShimano M8000 XT discShimano M8000 XT disc
ROTORSShimano RT66 180mm F / 160mm RShimano RT66 IceTech 180mm F / 160mm RShimano RT66 IceTech 180mm F / 160mm R
SEATPOSTRaceFace EvolveLoaded Components XLite (color choice)Loaded Components XLite (color choice)
SADDLEWTB RocketChromag TrailmasterChromag 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)Surly Clown Shoe, DT Swiss Comp spokes (handbuilt by REEB)
HUBSHope Pro4 FatsnoIndustry Nine Torch FatIndustry Nine Torch Fat
TIRESSurly Bud (front), Surly Nate (rear)Surly Bud (front), Surly Nate (rear) 120tpiVEE Tire SnowShoe 2XL 5.1"
RIM STRIPSurly (color choice)Surly (color choice)Surly (color choice)
VALVE STEMSSurlySurlySurly
REAR AXLE12x170mm12x170mm12x190mm
CRANK / BBRaceFace Aeffect Fatbike, RaceFace BBRaceFace Turbine Cinch Fatbike, RaceFace BBRaceFace Turbine Cinch 190 Fatbike, RaceFace BB
Shimano M7000 SLX 11-spd 11-42Shimano M8000 XT, 11-spd 11-42 Shimano M8000 XT, 11-spd 11-42
DERAILLEUR - REARShimano M7000 SLX 11-spdShimano M8000 XT 11-spdShimano M8000 XT 11-spd
RaceFace Narrow/Wide 30tRaceFace Narrow/Wide 30tRaceFace Narrow/Wide 30t
SHIFTERShimano M7000 SLX 11-spdShimano M8000 XT 11-spdShimano M8000 XT 11-spd
BELT/CHAINShimano HG601Shimano HG701Shimano HG701

Generic Geometry Chart

All measurements with the MRP Snowpack fork, 468mm A-C, 42mm offset.
Changes in fork will result in changes to certain aspects of the geometry.

 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 ANGLE69.0°69.0°69.0°69.0°
G. CHAIN STAY18.3"18.3"18.3"18.3"
H. HEAD TUBE4.1"4.5"5.1"5.5"
I. AXLE TO CROWN468mm468mm468mm468mm
J. OFFSET42mm42mm42mm42mm
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"