The WTB Frequency i23 offers one of the stiffest all mountain 650b(27.5") rims on the market, while still being light enough to pedal up the mountain. The WTB Frequency i23 is tubeless compliant and features their I-Beam Technology. We give you the choice to go with a Shimano build featuring Shimano XT hubs, or go all out with our fully convertible Pure D400 hubs. The D400 features 24 points of engagement with a 3 pawl free hub. These wheels are built with DT Swiss Competition Double Butted 2.0/1.8/2.0 spokes in a 32 hole configuration front and rear.