The BB30, named after the required axle diameter, is up to 100 grams lighter, has a lower Q-factor, more freedom from ankle and longer life. Other frame specifications and crank designs are required for this new standard. In addition to a 30 mm bottom bracket, the BB30 requires an extra-large frame retainer housing with a width of 68 mm or 73 mm as well as press-fit bearings secured by retaining rings.
