Super Light OCLV Mountain Carbon, IsoSpeed, tapered head tube, MicroTruss, Control Freak internal routing, balanced post-mount brake, Boost148 & G2 Geometry on M and larger sizes (Size S: 142x12mm rear hub) 29 Trek FSA IS-2, 1-1/8"" top, 1.5"" bottom

• OCLV Mountain Carbon - Trek's mountain-specific carbon fibre is tougher carbon, with unique materials and lay-up procedures, Trek's advanced engineering, and a higher standard of testing.

Procaliber SL is for the fastest XC riders. It's built with Super Light OCLV Mountain Carbon and delivers the unique trail-smoothing advantage of IsoSpeed, which takes the edge off fatiguing bumps in the trail so you can stay stronger for longer.