Simple, reliable square-taper bottom bracket setReplaces both the BB-UN26 and BB-UN55Sealed cartridge bearingAxe en Cr-MoFor bikes equipped with a chain guard, choose BB-UN300-KFor compatibility with an E-type front derailleur, choose BB-UN300-EWithout chainring bolts; Shimano FC-E6000 bolts recommended
Ultegra/105-level BB86 press-fit bottom bracketShimano, SM-BB72-41B, Press-fit, Shell: 86.5 mm, Dia.: 41 mm, Axle: 24 mm, Steel, Grey, ISMBB7241BCompatible with all Hollowtech II road cranksets