Features of the Mavic Ksyrium Disc Wheel No inner tube and no friction: the promise of low rolling resistance and increased speeds Decrease tire pressure for smoother driving and reduced risk of punctures UST System provides a perfect union between the tire and the wheel, facilitating installation, removal and maintenance Welded wheels machined with the ISM 4D process 19mm Internal width for low rolling resistance and increased comfort with 28mm tires Optimized placement of bearings Straight spokes and narrow profiles provide optimum rigidity