The 6Fattie will reside primarily with Matt, so expect to see a blur of red shooting down the rockiest lines at Tokai.

For those who aren't sure, 6Fattie is Specialized's name for 27.5+ sized wheels. These, in a nutshell, are wider 27.5 rims, run with 2.8 to 3" tyres. In terms of tyre width, this is somewhere between a 5" fat bike tyre and a commonly run 2.3" tyre.


The Stumpjumer 6Fattie is also compatible with 29er wheels, and we are really looking forward to swapping out the wheels to see how the wheel size affects the ride. This may be the two-bikes-in-one solution that some riders are looking for: and we can't wait to find out.

The Expert Carbon build

The Expert Carbon 6Fattie has a Fact 9m carbon frame, including the indescribably handy SWAT door in the down tube of the front triangle and a multitool stowed in the top tube. Squish is supplied by a 150 millimetre Rockshox Pike at the front, and a RockShox Monarch RT3 trail tune shock at the rear. Roval Traverse wheels wrapped in Purgatory 3" tyres provide traction. A RaceFace crank with a 28 tooth chainring powers a SRAM GX and X1 mixed drivetrain with SRAM Guide R stoppers.

But why Plus size?

The wider tyres provide a greater air volume and therefore more cushioning. They also have a greater contact area, providing huge amounts of grip and stability. With the increased depth that comes with a 27.5+ tyre, the final outer diameter is close to that of a 29er wheel, providing the improved rollover that comes with increased wheel size.



On the 6Fattie, this supposidly translates into monster truck capabilities while maintaining agile handling. With this bike, we'll be looking for the gnarliest line on the trail, all in the name of fun.

Stumpjumper FSR Expert Carbon 6Fattie specifciations

  • FrameFull Carbon Front Triangle, Full CaFACT 9m, carbon front chassis, M5 alloy rear end, Trail Geometry, SWAT™ Door integration, PF30 BB, fully enclosed internal cable routing, ManFu link, 12x148mm dropouts, sealed cartridge bearing pivots, replaceable derailleur hanger, 135mm of travel
  • ForkRockShox Pike RC 29/27.5+, Solo Air, compression and rebound adjust, tapered steerer, 15x110mm Maxle Stealth thru-axle, 51mm offset, 150mm travel
  • Rear ShockRockShox Monarch RT3, Rx Trail Tune, AUTOSAG, rebound and 3-position compression adjust, 197x48mm
  • CranksetRaceFace Aeffect, 6000-series alloy, 24mm spindle, 52mm chainline, 28T
  • Bottom BracketShimano BB-MT800 Pressfit
  • Front DerailleurN/A
  • Rear DerailleurSRAM X1 Type 2.1, 11-speed
  • ShifterSRAM GX, 11-speed, trigger
  • Front BrakeSRAM Guide R, hydraulic disc, organic pads, Guide S4 4-piston caliper, 200/180mm rotor
  • Rear BrakeSRAM Guide R, hydraulic disc, organic pads, Guide S4 4-piston caliper, 180/160mm rotor
  • CassetteSRAM XG-1150, 11-speed, 10-42t
  • ChainSRAM PC-1110, 11-speed w/PowerLink
  • PedalsN/A
  • RimsRoval Traverse 650, hookless alloy, 29mm inner width, 24/28h, tubeless ready
  • SpokesDT Swiss Revolution
  • Front HubRoval Traverse, sealed cartridge bearings, 15mm thru-axle, 110mm spacing, 24h
  • Rear HubRoval Traverse, DT Swiss internals, sealed cartridge bearings, SRAM XD driver body, 12mm thru-axle, 148mm spacing, 28h
  • TiresPurgatory, GRID casing, 650bx3.0", 60TPI, Aramid folding bead, 2Bliss Ready
  • HandlebarsSpecialized Trail, 7050 alloy, 8-degree backsweep, 6-degree upsweep, 25mm rise, 750mm width, 31.8mm
  • GripsSpecialized Sip Grip, half-waffle, S/M: regular thickness, L/XL: XL thickness
  • StemSpecialized Trail, 3D forged alloy, 4-bolt, 6-degree rise
  • SeatpostCommand Post IRcc, 12 position micro-height adjustable, alien head design, bottom mount cable routing, remote SRL lever, 30.9mm, S: 100mm, M/L/XL: 125mm travel
  • SaddleBody Geometry Henge Comp, hollow Cr-Mo rails, 143mm