BlackBox components are usually reserved for SRAM's elite riders, used as a testing and proving ground for the company's latest technologies and designs. The SRAM BlackBox Ceramic PF30 Bottom Bracket is the same that those top level athletes race on. It uses ABEC 1 rated bearings and advanced, low friction seals to ensure the PF30 BlackBox Ceramic Bottom Bracket gives nothing to friction. Silicon nitride ceramic ball bearings offer greater roundness and superior hardness compared to stainless steel alternatives. This substantially reduces mechanical drag. After aerodynamic drag, mechanical drag is the leading culprit in consuming the power you put into the pedals. Adding to this reduction of drag is Gutter Seal TechnologyGutter Seal Technology uses a unique seal design to drastically improve protection against water and dirt contamination without adding any additional drag. This boosts the bearing life and keeps downtime to a minimum. Nylon cups are pressed into the frame's bottom bracket shell 68mm for road and 73mm for mountain bikes. This setup is extremely lightweight, and offers a narrow Q factor to boost ankle clearance, which allows for enhanced crank and frame designs. The SRAM BlackBox Ceramic PF30 Bottom Bracket is compatible with SRAM cranksets with a 30mm spindle.