Specialized have quietly been revamping their line of mountain bike tires over the last year or so, modifying existing tread patterns with a little extra siping here, new knob profiles there, and more 2.6" options.
The Hillbilly is no exception, and the wet conditions specialist has been reworked to offer even more traction when the trails are muddy and soft. It now looks more like an aggressive version of Specialized's Butcher as opposed to a traditional mud spike, with tall, square knobs that have been spaced out to help keep the tire from getting clogged with mud.
Specialized Hillbilly Details
• Intended conditions: soft to intermediate terrain
• Gripton rubber compound
• Tubeless ready
• Sizes: 27.5 x 2.6", 29 x 2.6", 29 x 2.3" (tested)
• Weight: 980 grams
• Price: $60 USD
In addition to the new tread pattern, the Hillbilly uses Specialized's proprietary Gripton rubber compound, which is claimed to offer vibration damping properties that help keep the tire sticking to the ground in rougher sections of trail. It's the 29 x 2.3” Grid casing version that's tested here, but there are also 27.5 x 2.6” and 29 x 2.6” options available, all priced at $60 USD.
Tall side knobs help the Hillbilly dig deep into the ground.
There's more siping than the prior version, which helps deliver even more traction.
The Hillbilly was officially released only a few month ago, but I was able to get my hands on some early production samples late last winter, which means I've been able to subject them to plenty of muddy miles.
The installation and tubeless setup was hassle-free, and once installed on a rim with a 30mm internal width the Hillbilly measured a true-to-size 2.3” from side knob to side knob. As far as pressures go, I typically run 21 psi in the front, but I ended up going a couple pounds higher with these tires to get the sidewall support that I was looking for. The reinforced Grid casing is Specialized's answer to riders looking for more puncture resistance, although it's not quite as burly as what Maxxis offers with their DoubleDown casing – riders in extremely rocky areas may find themselves seeking even more protection. That being said, I didn't suffer any punctures over the course of the test period, although the trails I was on tended to have more roots than rocks, which aren't as likely to slice a sidewall.
Enough about casings and pressures – how does the Hillbilly handle the slop? Extremely well, with loads of traction available, even on harder surfaces – areas where this style of tire typically struggles. Compared to the Maxxis Shorty, the Hillbilly felt less likely to suddenly slide out when faced with the slimy roots and wet rocks that are common here in the Pacific Northwest, and it soon became my go-to front tire when trail conditions took a turn for the worse.
The Hillbilly isn't an all-rounder (and it's not billed as one) and on dry, hardpacked trails the taller knobs do have a tendency to squirm, especially during hard cornering. But when those trails turn to mud, the same knobs will dig right in with the tenacity of a rabid dog going after a buried bone, churning at the soil and providing massive amounts of grip. There were times when I found myself laughing out loud after exiting a turn – it's positively silly just how well this tire will lock-in and hold onto softer ground.
Even with such an aggressive tread pattern the Hillbilly's rolling resistance is reasonable. It's certainly not a ultra-fast rolling summer tire, but it never felt overly-sluggish either. I am curious about what running the 2.6” version in the front and rear would be like – I have a feeling that's a recipe for a really good time. As far as durability goes, tires last a lot longer when they're used in the mud rather than on rocky, hardpacked terrain, and this Hillbilly is still going strong, with enough tread left for another round of winter riding.