FATBACK CORVUS w/ WREN ATK 110 and carbon bash guards

FATBACK CORVUS w/ WREN ATK 110 and carbon bash guards

FAT BIKE FORK SELECTION

There are two main types of Fat Bike Forks, Rigid and Front Suspension.  Rigid forks are divided into Alloy and Carbon variants.  Fat Bike specific suspension forks are divided up into 5 different brand variants.  

Note: (PLUS+ size front suspensions are not covered in this FAQ)

FORK WEIGHT and TRAIL USABILITY COMPARISONS

CARBON RIGID FORK

  • 1.0 to 1.5 lbs
  • XC use only, AM possible but not advised unless expert rider.
  • no suspension travel (adjust tire PSI)
  • good for double-track riding in the snow and adventure biking

LAUF CARBONARA SUSPENSION FORK

Fatback Rhino w/Lauf Carbonara

Fatback Rhino w/Lauf Carbonara

  • 2.3 lbs
  • Lightweight all-carbon front suspension fork
  • XC use only - excellent for sprints, hill climbing, and quick steering.
  • Not recommended for AM use
  • Not recommended for slower, bumpy technical trails, where true suspension/rebound damping is required.
  • 60mm travel (max), progressive rate (LAUF states up to 15mm of constant travel at race speed)
  • Very fast rebound rate. 
  • "Zero maintenance"
  • Operates about the same in all temperature ranges
  • Most expensive Fat Bike suspension fork
  • Non-adjustable rebound rates, and non-existent damping rates.

ROCK SHOX BLUTO RCT3 SUSPENSION FORK

Fatback Skookum with Rock Shox BLUTO RCT3 120mm suspension fork.

Fatback Skookum with Rock Shox BLUTO RCT3 120mm suspension fork.

FOES MUTZ w/WREN 150 ATK suspension fork

FOES MUTZ w/WREN 150 ATK suspension fork

  • 3.9 lbs
  • XC and AM use
  • the original Fat bike suspension fork !
  • Excellent stability and control on light-to-medium ruts and rock gardens, as the BLUTO RCT3 is based off a cross-country Rockshox design.
  • As ride intensity and speed increases, this fork is known to flex or "noodle".  Steering becomes slightly sluggish, and fork is prone to bottoming out on very rough terrain.
  • 2 versions available :
    • 100mm (adjusts down to 80mm)
    • 120mm
  • Stops working outdoors when temps are sustained below about -15c, unless a special cold weather kit is installed to replace the stock seals.

CANNONDALE LEFTY OLAF SUSPENSION FORK

  • 5 lbs
  • XC and AM use
  • Excellent stability and control on ruts and rock gardens
  • Very plush ride, excellent fork  
  • Modern technology and design
  • 100mm travel
  • Requires a special hub/wheelset in order to function, which is a drawback for many looking for cross-compatibility.

WREN SUSPENSION FORK

Manitou Mastodon PRO

Manitou Mastodon PRO

  • 4.7 lbs
  • XC and AM use
  • Utilizes keyed stanchions (MUCH stiffer than a Bluto)
  • 2 versions of suspension fork available :
    • 110mm (adjusts from 80-100mm with token inserts)
    • 150mm (adjusts from 120-140mm with token inserts)
  • Surprisingly, even at 0.8 lbs heavier than a Bluto, the WREN is quicker and more responsive at steering, because its "Twin-Air" ATK version has been redesigned to eliminate flex.  You absolutely do not feel the extra weight.  It's a very agile suspension fork.
  • Includes a lockout switch for light-duty terrain and sprinting.  
  • "Twin-Air" chambers can be infinitely tuned for firm/plush suspension.  Wren fork excels the rougher the terrain gets.
  • Works fine down to -25c stock, and down to -50c with new Cold Weather Dampers.
    • Must use a suspension-corrected frame.
    • Takes some time to "dial in" and fine tune to the rider's trail needs via use of a shock pump and two air chambers, but once zeroed in, it's fantastic.  If not dialed in, you will know it. 
    • This suspension fork is for those that like to tinker a bit, and don't mind resetting air pressure to different trails or events.  (takes just a few minutes to do).   Once you know these trail settings for the Twin-Air chambers , the WREN becomes a very valuable piece of bike equipment and takes your trail riding to the next level.
    • Will be offered as custom build option on the new FOES MUTZ 150, and on all 2017 Fatback Bikes (Skookum, Corvus and Rhino FLT)

    MANITOU MASTODON SUSPENSION FORK

    • 5.0 lbs on the digital scale
    • Brand new for 2017 (COMP and PRO versions)
    • XC and AM use
    • 4 variants of suspension fork are available :
      • PRO model (has the most features, best spring and compression damping internals)
      • COMP model (base model to compete with Bluto)
      • STD ride height (for up to 26x4in / 27.5x3.8in tires)
      • EXT ride height (for up to 26x5.15in / 27.5x4.5in tires) 
    • 3 different length-adjustable versions of the suspension fork :
      • 00mm PRO or COMP (adjusts down to 80mm)
      • 120mm PRO or COMP (adjusts up to 140mm)
      • 150mm PRO (OEM version only)
    • Claimed to be 25% stiffer than leading competitor ("Bluto").
    • Must use a suspension corrected frame.
    • Brand new product - initial test rides have just begun.  First batches of the PRO version, now arriving in stock. (AUG 2017)
    • Will be offered as custom build option on the FOES MUTZ 150, Fatback Skookum, and the Fatback Rhino FLT.

     

    Mid Summer 2017 - online Industry reviews and factory test rider opinions show :

    • For ALL OUT PERFORMANCE, the WREN ATK 110 and 150 Series, and MASTODON 100/120/150 PRO STD/EXT models have taken over the reigns as the undisputed suspension leaders for fat bikes.  
    • Over the last 2 years, the BLUTO has shown signs of 3 major weaknesses :
      • BLUTO "Flexes", and exhibits "noodling" in steering when under high stress and high speeds. 
      • BLUTO "Bottoms-out" much easier than the latest editions of the WREN or MASTODON suspension forks.
      • BLUTO cannot handle 27.5 x 4.5 tires.
    • LAUF suspension is losing its popularity after riders take in its long-term affects :
      • Lack of damping
      • Very fast rebound rate
      • Rider absorbs most of the "trail shock" at slower speeds.
    • The LEFTY may be a great design, but its proprietary hub configuration and wheel-building requirements have limited its growth, and limited the wheelsets selections available to the rider, especially on the secondary market.
    • RIGID CARBON forks are evolving and becoming stronger and more capable, like the Fatback Carbon Cargo "anything" 3-rack mount fork.
    • As TIRE technology continues to improve, all-temperature traction and sidewall performance increases- resulting in better ride quality and less rim blow-offs or sidewall tears.  This allows tires to run higher pressure and the suspension forks to take on even more challenging terrain at higher speeds and impact rates.

    * ALL-OUT PERFORMANCE * TEST RESULT RANKINGS - AUG 2017

    WREN 110 ATK and MASTODON PRO suspension forks

    WREN 110 ATK and MASTODON PRO suspension forks

    1.  WREN ATK and MASTODON PRO series - currently tied, until more concurrent testing can be done

    2.  LEFTY OLAF

    3.  MASTODON COMP series

    4.  BLUTO RCT3

    5.  RIGID CARBON (coupled with large diameter tires and proper air pressure alignment)

    6.  LAUF CARBONARA (ranked 6th because of limited terrain use capability....it becomes a liability on some courses due to its very quick rebound, especially noticeable and affects handling and steering at slow speeds.  LAUF would rank 3rd if it was beach, gravel, pavement, or very light duty XC race conditions).  LAUF is zero-adjustable, and twice the weight of rigid carbon forks.

    7.  BLUTO RL (due to lack of adjustability in performance settings)