OSBB is the acronym for Specialized’s OverSized Bottom Bracket. It features a 46mm diameter and 61mm width shell. As it is unique, it requires a unique bottom bracket to mate BB30 cranks to it.
The cups come installed with one of two CeramicSpeed bearings. The Standard Bearing has ceramic CS balls and hardened-steel races. The Coated Bearing has the same balls running on hardened-steel races with a 3-micron thick metallic coating making the races harder and smoother, increasing service life and reducing friction.
The coated products have a 6 years warranty. The unique coating formula is a metallic layer that covers the bearing races and makes them 75% harder than steel. Thanks to this, they are highly resistant to corrosion and the coating provides an even lower friction than our standard bearings. Even if the bearing is contaminated with degreaser, water or mud, the risk of bearing failure due to corrosion is negligible if you choose the coated version.