Fit a Shimano Hollowtech II (24 mm) crank in a BB30 press fit shell
Whether a Shimano Hollowtech II (24 mm) crank fits a BB30 press fit shell, and the bottom bracket that makes it work.
The crank and the shell
| Crank spindle | Shimano Hollowtech II (24 mm) (24 mm constant diameter) |
|---|---|
| Frame shell | BB30 press fit (42 mm smooth press-fit bore, 68 mm (road) and 73 mm (MTB) wide) |
| Verdict | needs a reducer |
| Bottom bracket to buy | BB30 to 24 mm Shimano reducer bottom bracket |
SHELL BB30 press fit (42 mm smooth press-fit bore, 68 mm (road) and 73 mm (MTB) wide)
SPINDLE Shimano Hollowtech II (24 mm) (24 mm constant diameter)
BB BB30 to 24 mm Shimano reducer bottom bracket
SPINDLE Shimano Hollowtech II (24 mm) (24 mm constant diameter)
BB BB30 to 24 mm Shimano reducer bottom bracket
A 24 mm Shimano crank runs in a BB30 42 mm bore using a reducer BB that presses into the shell and carries a 24 mm bearing. The frame stays BB30; only the BB changes.
The 42 mm BB30 bore is tighter than PF30's 46 mm, so use the BB30-specific reducer. A PF30 reducer is too large to press into a 42 mm shell.
The bottom bracket to buy
Search Amazon for BB30 to 24 mm Shimano reducer bottom bracketaffiliate searchFind BB30 to 24 mm Shimano reducer bottom bracket on eBayaffiliate
Related fits
Shimano Hollowtech II (24 mm)24 mm spindleBB30 press fit42 mm bore press fitShimano Hollowtech II (24 mm) in a BSA / English threaded shelldrops inShimano Hollowtech II (24 mm) in a Italian threaded shelldrops inShimano Hollowtech II (24 mm) in a T47 external (T47-68 / T47-73) shelldrops inShimano Hollowtech II (24 mm) in a PF30 press fit shellneeds a reducer
SOURCES: Park Tool, Bottom Bracket Standards and Terminology · Wheels Manufacturing, Crankset Spindle Standards & BB Compatibility · Wheels Manufacturing, Three Common Bottom Bracket Misconceptions