Dirt Wizards – Surly Does it Again

By – Ken Blakey-Shell


I have to start out by saying that while excited to get a pair of Surly’s 29 x 3.0 Dirt Wizards to try, this isn’t my typical kind of tire for where I ride so I was a bit apprehensive about testing them. The Dirt Wizard is kind of a niche tire with its big aggressive knobs and slightly “smaller” casing. Would they just be slow and excessively grippy or could I find terrain where they offered an advantage? The short answer is that they are surprisingly versatile and excel when things get muddy or super knarly. Long answer to follow.

If you are interested in the specs of these tires, check out Grand Poobah Gomez’s First Contact write-up. I mounted the 29-plus Dirt Wizards up tubeless on my 35mm (30mm interior width) rims and they snapped right into place with minimal to no issues getting them to seal up. Exactly what I want to experience in this day and age of tubeless enlightenment.


Living in Northern Michigan, we have an abundance of traditional midwest singletrack that ranges from buffed out IMBA spec to fairly eroded, trenched and rooty old school singletrack. None of this really seemed to fall into the strengths of the Dirt Wizards. Luckily, as soon as I saw the Wizards mounted up I knew I wanted to give them a go on our local moto trail singletrack. Michigan moto riders are fortunate to have the Michigan Cross Country Cycle Trail (MCCCT) which is a 1,200 mile moto trail that forms an “arch” up and around the Lower Peninsula of Michigan. What does this have to do with riding a bicycle? Well the moto trails happen to offer up some of the best technical mountain biking in the LP as long as you are riding a plus or fat bike (too loose for zombie bikes). We are still discovering what these trails have to offer but there is a classic section in the Caberfae region that had “Dirt Wizard” written all over it. This section consists of great topography, super steep ups and downs, lots of ledges and exposed roots and then the usual “churn” of the top 1-2” of soil along with a healthy dose of mud in low lying areas. The big meaty lugs and decent volume casing seemed like a natural for these conditions.

We got out after a period of rain so the trail was fairly moist and firm. With the big knobs I expected the tires to roll slowly but I was immediately impressed with how well they rolled. The guys I was riding with were on Chupacabras and Knards and I didn’t notice a big difference in rolling resistance. I am guessing it is all the ramps on the knobs but whatever magic juju Surly has baked into these treads, it really extends the range of conditions for the tires. Maybe it has something to do with the fact that the center knobs primarily contact the ground making it so that it rolls like a more narrow tire?


Even in sand, only the center knobs make contact with the ground

Some aggressively knobbed tires are “grabby” and causing the transition between gripping and sliding to be harsh, jerking the bike around. The Dirt Wizards didn’t exhibit this characteristic and seemed to transition from super grip to a feeling I can only describe as “carving.” The only comparison I have is to skiing or snowboarding where you can use the edge and carve around corners. The Dirt Wizards did the same thing with the tall and almost continuous side knobs giving a great sense of control even with both tires drifting in a corner. These are tires that like to go at supersonic speeds, rewarding those that push the envelope.


Holy side knobs batman!

Mud performance was excellent. The Dirt Wizards shed mud really well and never packing up. I didn’t get into super heavy clay-based mud but the clay/organic material combo I was in (that packs in other 29+ tires) didn’t pack up at all. Drive and cornering traction were both excellent in the mud. These tires were so much better than what I normally ride that it took a whole 3 hour ride before I had reset my “I am going to die in this corner” mental governor and found the edge of control in muddy corners.

The rubber compound seems to be very similar to the Knard. That is a good thing when it comes to traction because it is a fairly soft compound and grips really well. The flip side is that you are going to lose the sharp edges on your knobs and may rip knobs fairly quickly if you ride really hard. For instance, even after a single hard ride where I was really pushing the tires I could see where parts of knobs had been worn down.


Wear on knobs after a couple hard rides

I rode these tires on a lot of other trails ranging from buff to rooty and bumpy singletrack as well as hitting some sandy two tracks that the plus tires generally excel at. On harder trail surface conditions I continued to be impressed with how well the tires rolled, but the big knobs didn’t do a whole lot to increase traction compared to other plus options with less aggressive treads. Luckily, the big knobs didn’t seem to get squirmy under hard cornering loads so there were not any big disadvantages in these conditions. The big knobs do make the tires feel REALLY slow in sandy conditions. This won’t come as a surprise to any fat-bikers that ride the beach but the surface area or the way the big knobs churn sand really causes a ton of drag. When going through deep dry sand, I felt like I had pulled a ripcord on a parachute because I got instantly dropped when riding with other plus bikes.


Well supported side knobs

I do have to note that this was the first 29+ tire I have ridden where I wished I had a 50mm rim instead of my narrower 35mm rim. Then those big knobs really hook up but all that traction with the ground can easily overload the casing at normal riding pressures, causing the tire to feel floppy in corners.

For my local trails, I wouldn’t put these on that frequently but if I was headed somewhere with typically wet conditions and a lot of rocks and roots (Pisgah here I come!), this would be my go-to tire. By no means is this an “allrounder” but hats off to Surly for offering up another 29+ product that pushes the envelope and expands the range where plus bikes can excel.

For more information about Surly bikes and tires, visit – http://surlybikes.com/

4 Comments on "Dirt Wizards – Surly Does it Again"

  1. So what’s your current favorite allrounder tire for N Michigan?

  2. The 50mm rim isn’t helping my situation in terms of the carcass giving away under cornering load. I’ve been up to 25 psi, at which point the folding over seems to lessen, probably due to the fact that it was loosing traction because of tire rebound and not being able to conform to surface irregularities.seems to degra

  3. Ken Blakey-Shell | July 29, 2015 at 9:57 am | Reply

    My favorite current favorite Northern Michigan tire is the Bontrager Chupacabra. It seems to do everything well, is holding up great and is on the lighter end of the spectrum for 29+ tires. If you want to go a bit lighter and don’t need the volume, the Panaracer Fat B Nimble (which measures about 0.15″ smaller in width) is a great option also.

  4. Did you ride these at Arcadia Dunes? I’m assuming they would be slower than Knards / Chupas on that type of trail – especially if it’s dry (although I did feel like the Knards are at the limit in some of the corners when the course is dry).

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