Wheels Manufacturing T47 Outboard Bottom Bracket - For 30mm Spindle, ABEC-3 Bearings, Fits Frames with 68mm-100mm BBT47 Outboard threaded bottom brackets are made from machined aluminum, and thread together directly into T47 frames. Cups have outboard bearings, and are typically used in BB shells with widths from 68mm to 100mm. For use 30mm crank spindles in frames with T47 interface Fits 68mm 100mm shell widths Enduro ABEC 3 sealed bearings are replaceable Grade 10 chromium steel balls, 52100 High Carbon Chromium Alloy Races provide smooth crank rotation Machined