Shimano Ultegra BB72-41B Bottom Bracket The Shimano Ultegra BB72-41B Bottom Bracket is used with BB86/92 bottom bracket shells and is compatible with 24mm spindle Shimano Hollowtech II cranksets. This bottom bracket lives up to the quality you expect from Shimano. Features Model Number:SM-BB72-41With reliable SHIMANO bearings and seals, the SHIMANO ULTEGRA bottom bracket has a long service life. Press-Fit BB Shell Width: 86mm BB Shell Internal Diameter: 41Weight: 69g | Shimano | Ultegra Bb72-41B Bottom Bracket | Black | Bb86/92