The Specialized Ground Control 2Bliss Ready Tyre with our new Control casing, delivers plenty of versatility and flat protection. Not only does it feature improved cut-resistance, but we've also optimized the tread using Finite Element Analysis. It also features our own GRIPTON® compound that maximizes mechanical grip, damps vibration, and offers unparalleled traction in either wet or dry conditions. Specialized Ground Control 2Bliss Ready Tyre Features Casing: 60 TPI Bead: Foldable Butyl wrapped bead = 2Bliss Ready Compound: GRIPTON® 26 x 2.1, psi 25-50, approximate weight 580g 26 x 2.3, psi 25-50, approximate weight 620g 27.5 x 2.3, psi 25-50, approximate weight 670g 29 x 2.1, psi 25-50, approximate weight 640g 29 x 2.3, psi 25-50, approximate weight 740g