Surly Dirt Wizard Tire - 27.5 x 2.8 Tubeless Folding Black/Slate 60 tpiSurly Dirt Wizard Tire 27. 5 x 2. 8 Tubeless Folding Black Slate 60 tpi. 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. TECH SPECS Color Black Slate Flat Protection Tread and Sidewall TPI 60 Weight 1250 Defined