The central BB92 movement is Press Fit in frames with a 41mm diameter wide 89.5/91.5mm and adapts most cranks with a 30mm spindle to the standard one. If you have a BB92 frame and want to install a 30mm crank, this is the kit you need. The CeramicSpeed bearings are installed in cartridges. The balls roll on hardened steel races with a 3-micron thick metal coating that makes the races harder and smoother, increasing service life and reducing friction. This MTB version comes with the long-lasting CeramicSpeed grease applied in the bearings optimized for off-road use. All CeramicSpeed Coated products come with a lifetime warranty.