650B

The Ground Control Sport is an exceptionally versatile trail tire that uses a tread optimized using Finite Element Analysis. This means that it rolls fast and provides increased grip and traction in nearly all conditions. Casing: 60 TPI Bead: Wire Compound: 60a 26 x 2.1", psi 25-50 26 x 2.3", psi 25-50 27.5 x 2.3", psi 25-50 29 x 2.1", psi 25-50 29 x 2.3", psi 25-50 29 x 2.3", psi 25-50

Specialized's Hardrock'R is a long-lasting tire with an aggressive, yet smooth-rolling tread with multi-directional knobs that are sure to improve traction and cornering over mixed terrain. And with the added benefit of its Flak Jacket flat protection, you'll be sure to hit it all with confidence and control. - Casing: 30 TPI - Bead: Wire - Compound: 70a - Flat Protection: Flak Jacket - 26 x 2.0"; psi 35-65; approximate weight 880g - 650b x 2.0"; psi 35-65; approximate weight 960g - 29 x 2.0"; psi 35-65; approximate weight 1000g