At SRAM, we saw the opportunity to develop a better PressFit system, combining all the benefits of the BB30 and PressFit bottom brackets into one fantastic package. The PressFit 30 has a pre-assembled seal in the cups to extend bearing life even further. For PressFit 30, the major difference is the way in which the bearings fit into the frame. These are in nylon shells, which are pressed into the bottom bracket shell of the frame. This bottom bracket is designed for 30mm bottom bracket shafts.
The frame retainer must have an inside diameter of 46 mm in order to use this system. PressFit 30 for road bikes requires a 68 mm wide housing, while PressFit 30 for MTB requires a 73 mm wide housing.