Pronounced 'cross king', the X-King perfectly fills the gap between our Race King and Mountain King II in terms of application. It was developed in conjunction with the Topeak-Ergon professional MTB team who have now recorded numerous race wins on what they call the 'perfect race day tire'. The symmetrically-designed tread pattern provides ample traction, yet with the minimal rolling resistance of a much less aggressive pattern. The 2.4 option appeals to enduro applications where terrain dictates larger volume, but less weight, yet the 2.2 rolls like the wind while still providing ample control.