The trek x caliber 8 hardtail mountain bike 2016 packs all of trekrsquos xc race hardtail experience into a light fast race ready bike that pairs the right wheel size with each frame size nothing beats the efficiency simplicity and straight up fun of x caliber 8 in 29er or 275 this trek hardtail mountain bike features a highly refined alpha aluminium frame which uses sophisticated tube shaping to minimise weight and maximise race day performance the simplicity and lightness of a 2x10 dr