Specialized Hillbilly BLCK DMND is not a lightweight tyre. Fit this tyre to a trail bike and it’s draggy uphill and slow to accelerate.

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Although the Hillbilly is a mud tyre, it’s features Specialized’s new BLCK DMND casing, which is also used on two dry-weather friendly tyres the Specialized Butcher and Specialized Eliminator. This casing is designed for Enduro and downhill use and is double thickness with overlapping plies. This adds weight but it does mean the BLCK DMND series is a great option for e-bikes, and since I spent the whole winter on one, I fitted a set of Hillbilly tyres at the beginning of the rainy season to see how they’d hold up.

The tyre also features Specialized’s new Gripton rubber compound but I don’t feel it’s as soft or tacky as the compound used for the old Hillybilly, and if you run a bit too much air pressure (I reckon over 20psi) it does skate around a lot more. Running lower (sub 20psi) pressure, which is something I tend to do as a matter of course when using wider 2.6 and 2.8in tyres, does increases the tyre deformation and mitigates some of this sketchiness but this can cause the tyre to roll lightly when loading the bike into turns, which presents its own set of problems.

To really get a feel for the new Gripton rubber I also ran the regular 2.6in Hillbilly with the thinner Grid casing for a short period on my regular trail bike. The Grid sidewall is lighter but didn’t offer the same sort of support as the BLCK DMND casing and that meant I had to up the pressure, which made it feel really nervous in wet and slippery conditions. The tyre also felt pingy on roots and flinty surfaces, which I could only put down to the harder rubber compound.

As a tyre for e-bike use, the Hillbilly BLCK DMND feels solid and supportive. It’s not as surefooted as a Maxxis 3C, but you can increase grip by running slightly lower pressures especially if you set up the tyres tubeless.

In previous winter tyre tests, MBR has recommended the Specialized Hillbilly because it had soft rubber and was great value but with the change compound and price hike, the new Hillbilly is not the tyre it was and this is reflected in the rating.