Tool-less type thru-axle skewer system optimizes rigidity and weight balance and enables easy operation with reliable internal cam mechanism and new fixing structure. 15mm thru-axle system are15% stiffer torsionally and 25% stiffer in transverse shear than a traditional 9mm QR front axle system. 8mm thru-axle system for trekking/hybrid hub and dynamo hub are also available.