Specialized has updated the Hillbilly mountain bike tire, their answer to the steepest and softest, or loosest conditions offered up by mother nature. It maintains the widely spaced tread block pattern of the previous iteration, the most notable alteration coming in the form of block-in-block transition knobs at the edge, said to add reinforcement and stability when plowing deep into soft loam or railing rock slabs. Available in Grid Trail and Grid Gravity casings, its tread pattern is made up of Specialized’s stickiest, lowest rebound T9 rubber, prioritizing out-and-out grip over rolling resistance and durability. Sizing options include 29″ x 2.4″ and 27.5″ x 2.4″.

While the super soft, slippery trail conditions we’re accustomed to have been absent for many months, they have given way to some of the loosest, marble-like conditions I’ve ever seen in this valley. Here’s how our first ride went.
New Specialized Hillbilly
I tested the 29″ x 2.4″ Specialized Hillbilly in the Grid Gravity casing, with a tubeless setup, on the SCOR 4060 LT I’ve been testing for the last few weeks. After wrestling the tough carcass onto the rim of a Crankbrothers Synthesis aluminum wheel I struggled to get rapid enough inflation to seat the tire with a Topeak Joe Blow Sport pump. I resorted to the use of my trusty Air Shot, and was successful thereafter. With sealant injected via the valve core, and pressure adjusted to 17 PSI, I was good to go.
Yes, 17 PSI is low. Much lower than that recommended on the tire casing. Here you’ll see a warning not to ride the tire below a minimum pressure of 25 PSI. Weighing just 61.5 kg in a full riding kit, and given the GRID Gravity casing of the tire, I wasn’t at all concerned. Besides, I find most tires, particularly those with a tough casing, perform best at pressures considerably lower than the manufacturer’s minimum recommendation.

My experience of the new Specialized Hillbilly is limited to one short ride, so I’ll keep this brief. Also, I’ve no previous experience of the former Specialized Hillbilly, so can’t provide a comparison.
In the loose, marble-like conditions of some of the over-ridden, over-baked trails, the Hillbilly’s connection with the terrain was confidence-inspiring from the off. Though you’ll see the marketing weighted heavily toward, slippery, loamy conditions, my experience is that it deals very well with loose-over-hardpack conditions. I’ve not yet been able to test it in the aforementioned quagmire.

Pricing & Availability
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27.5″ and 29″ x 2.4″ Grid Gravity T9 will retail at €70 or $75 USD
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27.5″ and 29″ x 2.4″ Grid Trail T9 will retail at €60 and $70 USD