Surly’s family of Dirt Wizards is highly-focused – one might even say spellbound – on providing traction and control on the kinds of surfaces where nary traction nor control are to be found. Its tread is comprised of a dual row of aggressive, trail-gobbling, beveled knobs in the center and well-spaced, siped knobs to dig into loose corners. Designed to work on 50mm rims, Dirt Wizards are tall and wide, providing next-level traction and cushioning. The casings have been designed to be flexible and responsive, yet durable and supportive. Minimum rim size for these naughty little wizards is a 35mm outer rim width.