Surly Dirt Wizard Tire - 27.5 x 2.8 Tubless Folding Black 60tpi. The Dirt Wizard will cast a spell on the trail… a spell that will conjure all the traction and control you will need to slay the trail dragon. Dirt Wizard features a Nylon anti-cut sidewall insert. The new Surly rubber compound design for longer wear and better performance on the trail.