DT Swiss 240 DEG Classic Flange IS Disc Rear Hubs. Features: Size-optimized 90 tooth ratchets provide DT's fastest engaging hub; 4 degree With DT's 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 of Ratchet System hubs 6-bolt disc Steel cartridge bearings Refined end caps allow for easier disassembly DT Swiss spoke calculator: https://spokes-calculator.dtswiss.com/en/calculator Specs: Front Rear:rear (XD) Axle Spacing Mm:12X148 Boost Hole:28h Color:black/red Weight:255g