Presenting our beautiful BB30 External Bottom Brackets with World Champion original ACER Racing Ceramic ball bearings. You already know of the extreme advantages of ACER Racing ceramic bearings. The lower friction and lower rolling resistance of our ceramic ball bearings result in drastic drag reductions, which translate to the equivalent of considerable static weight deductions on your bicycle, allowing you to achieve higher speeds with less effort. Our External Bottom Brackets are made from forged and CNC-machined alloy cups. Net weight is only 82 grams. English threads 1.37"x24TPI for 68mm shell. For Shimano Road Cranksets that have 24mm thru-axle spindles. Available in Red Anodized.