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
• Only compatible with 73 mm bottom bracket shells• No English BSA threading (1.37 in x 24 TPI)• Dual sealed cartridge bearing construction with steel body, axle and cups• Interface S.I.J. (carrée) standard• Weight: 338 g (113 mm)