Updated EXP (expanding friction disk) assembly, Base material updated to provide better strength in high temperature environments, critical for the heat clutch systems create, Internal wall bases redesigned for strength and rigidity, which helps translate to a more connected lever feel for the rider, On the outside of the EXP disk, friction pads now match proprietary friction design found on Rekluse TorqDrive clutch plates, this design helps match oil flow characteristics on the clutch pack beneath, promoting improved cooling capability and consistent operation, EXP 4.0 wedges have been improved to now use rolling contact with built-in pins, Rolling pins versus sliding creates less friction and resistance, providing smoother engagement and a more responsive feel, creating stronger power delivery overall, More direct power delivery, improved durability, and rider-focused functionality, Engagement curve designs updated to better match modern motorcycle engine characteristics, More tuning options with varying wedge weights and EXP springs