(Review) Monkey Rides: Tyler’s Surly Krampus 29+ Mountain Bike With Rohloff SPEEDHUB 500/14 and Gates Belt Drive

Tyler's Krampus set up for aggressive trail riding. 

Tyler, one of the newest Monkeys on our team, was an early adopter of Surly’s Krampus, a new style of bike Surly introduced last year that they call “29 +.” The three inch wide tires on 50mm wide 29 inch rims provide the float and traction of a fatbike, but the speed and maneuverability of a 29er mountain bike. Tyler loves his Krampus, but wanted a Rohloff SPEEDHUB and a Gates carbon belt drive to clean up the drivetrain and simplify the ride. His aim was straightforward - create a streamlined, aggressive all-around trailbike.

First off, we sent off the sparkle green frame (Surly calls the color “moonlit swamp”) to get a small splitter installed on the seatstay so we could fit a belt drive through the frame. The frame came back a few days later (along with some other belt drive modification projects you’ll see soon) and we set to work.

 

We sent off the Krampus to get a small belt drive splitter installed in the frame.

The wheel build consisted of a Rohloff SPEEDHUB 500/14 and a DT Swiss 240s front hub. Using Sapim 14 gauge spokes for strength, we laced the hubs to Surly’s 50mm wide Rabbit Hole rims. Surly’s 29x3.0 Knard tires rounded off the wheelset.

We chose Shimano SLX hydraulic brakes to provide more stopping power than the mechanical brakes that come spec’d on the stock Krampus, and used 160mm brake rotors front and rear. Our Monkey Bone brake adapter keeps the SPEEDHUB’s OEM2 axle plate secured in place.

The centerpiece of the build was the SPEEDHUB 500/14. Tyler knew that front derailleur and chain clearance has always been an issue with fatbikes, especially with a triple crankset. The SPEEDHUB solves this problem by completely removing a front derailleur from the equation while still reaching a 526% gear ratio – comparable to most full MTB derailleur systems. The SPEEDHUB also allows gears to be changed at any time without pedaling, which helps with technical singletrack and quick changes in trail terrain.

 

Rohloff SPEEDHUB and Gates Carbon Belt drive are
the perfect combo for the Krampus.

The Krampus comes stock with a rigid steel fork, but we installed Fox’s F29 fork to make a more versatile trail machine. With three inch wide tires, the clearance was a concern at first, but the tire clears the fork arch just fine. Tyler may eventually upgrade to a fork with a larger arch for more mud clearance in winter, but he’s happy with the setup for now. He also sees a tubeless conversion in the future, which would shave off a bit of weight.

Tyler has been riding the bike hard on the local trails, and he says it’s the most versatile hardtail he’s ever ridden – nimble and quick, with enough suspension in the fork and tires to roll right over the rough stuff. We’re looking forward to conducting more Krampus experiments in the Monkey Lab in the future. Contact us if you want us to set one up for you!

Build Details:

·  Frame: Surly Krampus 21”

·  Fork: Fox Shox F29 120mm

·  Headset: Cane Creek 40-Series

·  Stem: Thompson Elite X4 31.8mm

·  Handlebar: Syntace Vector High Five alloy 800mm wide

·  Shifter: Rohloff

·  Grips: Syntace Screw-On Moto

·  Seatpost: Cannondale Flash Carbon

·  Saddle: Specialized

·  Seat Clamp: Salsa Quick Release

·  Front Hub: DT Swiss 240s

·  Rear hub: Rohloff SPEEDHUB 500/14

·  Spokes: Sapim

·  Nipples: Sapim brass

·  Rims: Surly Rabbit Hole

·  Tires: Surly Knard 29x3.0”

·  Cranks: RaceFace Turbine SL

·  Bottom Bracket: Chris King

·  Chainring: Gates 4-bolt 46t

·  Rear Sprocket: Gates 20t

·  Chain: Gates Belt Drive

·  Brakes & Levers: Shimano SLX

·  Rotors: Shimano SLX