20 January 2014

Monkey Ride: Tyler's 29+ Surly Krampus Mountain Bike with RohloffSPEEDHUB 500/14

Tyler here at Cycle Monkey has a bit of a fat tire fetish. He also has a bit of a Surly fetish. It sometimes seems as if he has almost as many Surly bikes as he does Surly T-shirts, and he's been known to wear a different Surly tee every day for two weeks straight - with socks to match just to show off. This bike is one of his recent creations - a Surly Krampus with 29x3.0" Surly Knard tires and a Rohloff SPEEDHUB 500/14 internally geared drivetrain.

Technically, the Krampus is a 29+ bike, not a fatbike. Although the 29x3.0" tires on the Krampus seem gigantic, they aren't quite wide enough to give the bike the flotation needed on soft-packed snow and sand.

This new 29+ wheel format has gotten a fair amount of attention since the Krampus was announced, and Paragon Machine Works has even created a special chainstay yoke to allow small builders to create their own 29+ monster bikes. We expect many more exciting 29+ options to be released within the next few years.

Above all, Surly's designers wanted the bike to be fun to ride fast, with the rider's weight more over the back wheel to make it easier to roll or hop over roots, rocks and off-camber dirt. To accomplish this, the Krampus has a 69.5 degree head tube angle, which is 2-3 degrees slacker than most fully rigid bikes, and a taller bottom bracket. The top tube is also a bit longer to address toe overlap with the front wheel. Surly recommends a short stem with this setup to keep the steering sharp, so Tyler chose a stubby 40mm stem and extra-wide 800mm downhill handlebar.

To give this rigid bike even more compliance on rough trails, Tyler used a Cannondale SAVE carbon seatpost (disguised with a large Surly sticker), which has a flattened shaft that flexes while riding. Although the post visibly bends by a few millimeters, it is plenty strong - Tyler is a big guy and hasn't had any issues with it.

Tyler says it's hard to jump on a bike like this and not have a smile on your face. It's also hard to resist compulsively plowing over small objects, jumping off curbs or riding down stairs. The rest of the Cycle Monkey team likes Tyler's bike enough that we're planning to build up our own Krampuses.

If you can't resist the urge to feel like a little kid on a bike again, give us a call to see what kind of fat-tired ride we can put together for you!

Build details:

• Frame: Surly Krampus XL
• Fork: Surly Krampus
• Headset: Cane Creek Forty
• Stem: Syntace 40mm
• Handlebar: Syntace Vector 800mm
• Shifter: Rohloff
• Grips: Syntace
• Seatpost: Cannondale SAVE
• Saddle: Specialized Phenom
• Front Hub: DT Swiss 240s
• Rear Hub: Rohloff SPEEDHUB 500/14
• Spokes: DT Swiss Champion
• Nipples: DT Brass
• Rims: Surly Rabbit Hole
• Tires: Surly Knard
• Front Skewer: DT RWS
• Cranks: Race Face Turbine
• Bottom Bracket: Chris King
• Chainring: Race Face Single Ring
• Rear Sprocket: Rohloff sprocket
• Chain: Wippermann 8sX
• Brakes & Levers: Shimano SLX
• Rotors: Magura 180mm/180mm


  1. Neil,

    I was wondering if you could shed some light on mounting the rear wheel on the Krampus. Do you have to remove the rear caliper (i.e. Monkey Bone) every time you remove or install the wheel? I can't seem to simultaneously align the axle plate with the Monkey Bone and my threaded axle with the drops.

    This hasn't been a problem in the past with Surly's track-style drops so it's entirely possible I'm missing something.


  2. Yes, the caliper needs to be swung out of the way to allow the rotor to pass and the OEM2 plate to release from the Monkey Bone. I remove the lower bolt on my Krampus and loosen the top one but leave it in place. I don't have any experience with a non-Rohloff setup on these bikes to compare against, but moving the brake is normal for us.