Smooth! The best external bottom bracket currently available. External bottom brackets have been plagued with low durability - the smaller bearing has to handle more forces, it's wide open to water and mud ingress and the install splines can get real notchy after a few removal/installs. MSC Components BB24 bottom bracket features large angular contact bearings (like the ones you get in your headset) this means they can be pre-loaded without binding up and running rough, in addition to the 2x seal on the bearing itself they are cased inside the smooth housing which is double sealed with o-rings. It's installed with an ISIS spline adapter and gives that crank / bottom bracket area are really nice clean finish. You can install and remove it as many times as you want and it will always look nice and new. weight:80g Camptible with Shimano bb24 systems Dual angular contact bearings Double o-ring weather seal Hard anodised finished.
