DT Swiss 240 EXP SP CL-Disc Rear Hub 28h 12x148mm XDRatchet EXP (36t) features a fused threaded ring ratchet and single spring, reducing the number of components for a lighter and more durable freehub system Integration of drive side bearing into threaded ring widens bearing stance, resulting in 15% greater hub stiffness With DTs ratchet system, all of the teeth on each side of the ratchets engage simultaneously every time. This creates much smaller point loads and results in the legendary reliability