A benchmark of benchmarks.
The superb reliability of the DT Swiss 240s Rear Road Hub has been proven in the form of the fact that countless top-notch wheel manufacturers use 240 hubs to build their wheels. They are virtually faultless, with low weight, impeccable smoothness, and they're virtually maintenance-free, so if you've ever wanted to build your dream wheelset, this is a great place to start.
The 240s rear hubs use a forged aluminum shell that houses stainless steel bearings (balls and races), which are known for their famous durability. And thanks to the DT Swiss labyrinth seal system — non-contacting seals that utilize an asymmetrical path to resist moisture, muck, and grit — your bearings will keep their magical smoothness over the long haul. In addition to the way it sings on fast descents, the 240s' Star Ratchet freehub system is legendary for its simplicity, durability, and instant power transfer. The ratcheting freehub offers tool-free access for routine cleaning and lubrication, and the freehub body is made of aluminum to maintain a lightweight package.
Thanks to the fact that we now live in a world of 10- and 11-speed drivetrains, many of your hub and wheelset options have asymmetrical, highly dished rear wheels. This asymmetry doesn't allow adequate spoke tension on the non-drive side of the wheel, causing unequal loads and an inherently weak wheel. DT Swiss concentrated on this problem when they developed the 240s Rear Hub. Its optimized flange geometry improves the wheel's symmetry, giving you tons of reliability and resistance to detensioning.
DT Swiss manufactures the 240s Road Rear Hub with three drillings — 24, 28, and 32 hole, and it's currently available with an 11-speed-ready SRAM/Shimano-compatible freehub body only.