Rotor's Self Aligning Ceramic MTB Bottom Bracket is made with ceramic hybrid bearings to lessen the resistance to your pedaling efforts. The design of the bottom bracket cups goes one further. The self alignment of the Rotor assembly maintains perfectly parallel bearings for maximum efficiency and drag-free performance. The ceramic cartridge bearings have the ability to swivel by a few degrees, negating any problems with bottom bracket shell alignment or lack of proper facing.
To accomplish this, the Rotor bearings fit into thin nylon sleeves that then act with the CNC machined 7075 aluminum cup like a ball and socket. This system requires no more maintenance than existing bottom bracket systems and should be regarded as "set and forget". However, should the cartridge bearings ever need to be replaced after normal wear, they can be replaced by hand, with no special tools. It's made to be used with 68 and 73mm shells with English threading and is compatible with E-type Shimano derailleurs. It can be used with Rotor and Shimano cranks or any of a number of cranksets that are manufactured using Shimano's specs.
The Rotor Self Aligning Ceramic Bottom Bracket has red anodized alloy cups. The actual weight of the bottom bracket assembly is 96 grams.