Fit a Shimano Hollowtech II (24 mm) crank in a Trek BB90 press fit (road) shell
Whether a Shimano Hollowtech II (24 mm) crank fits a Trek BB90 press fit (road) shell, and the bottom bracket that makes it work.
| Crank spindle | Shimano Hollowtech II (24 mm) (24 mm constant diameter) |
|---|---|
| Frame shell | Trek BB90 press fit (road) (37 mm smooth press-fit bore, 90.5 mm wide) |
| Verdict | drops in |
| Bottom bracket to buy | BB90 bottom bracket bearings for a 24 mm Shimano crank |
SPINDLE Shimano Hollowtech II (24 mm) (24 mm constant diameter)
BB BB90 bottom bracket bearings for a 24 mm Shimano crank
A 24 mm Shimano Hollowtech II crank is the native and only sensible fit for a Trek BB90 shell. The cartridge bearings press straight into the 37 mm carbon seats and carry the 24 mm axle with no cup.
The 37 mm bore is too small for a 30 mm crank, so BB90 is effectively 24 mm only. Press new bearings with a proper tool because the carbon seat can be damaged if a bearing goes in cocked.
SOURCES: Park Tool, Bottom Bracket Standards and Terminology · Wheels Manufacturing, Crankset Spindle Standards & BB Compatibility · Wheels Manufacturing, Trek BB90/95 Technical Info · BikeRadar, I won't miss BB90, the worst bottom bracket standard