Shimano dura ace 9000 road rear hub elite road racers demand the best dura ace components are precision engineered for ultimate performance and durability the dura ace 9000 road rear hub features an oversized alloy axle for increased rigidity and an improved freehub design for faster engagement and instant power transfer features improved freehub body design for quick pawl engagement for instant power transfer oversized axle has increased rigidity both torsionally and laterally removing axle