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 6bolt disc Steel cartridge bearings Refined end caps allow for easier disassembly DT Swiss spoke calculator: https://spokescalculator.dtswiss.com/en/calculator