Rotor applies its new Double Thread Technology (DTT) Evo Technology to the faceplate and the steerer clamp of their S2 Evo Stem to achieve increased clamping force. The DTT Evo bolts have also been redesigned with a new dual-thread pitch and use a T25 Torx head. Using a T25 design allows for reliable tightening without rounding out the head of the bolt, in turn ensuring reliable clamping regardless of the handlebar used. The Rotor S2 Evo Stem tips the scale at 99 grams. Price: $200 More: rotorbikeusa.com