Using not only rider feedback experience & knowledge weve taken tread design a step further by manipulating each knob of the Fast Trak with FE Analysis. The result is less rolling resistance more traction when you need it all in a lightweight package. Adaptive Tread technology for Competitive XC riders. Casing: 120 TPIBead: Foldable Butyl wrapped bead = 2 Bliss Ready Compound: 60a 26" x 2.0; psi 35-65