What bottom bracket does a Specialized Aethos (2021 on) use?
The bottom bracket shell standard on a Specialized Aethos (2021 on), and how to pick the right BB.
This frame's shell
| Frame | Specialized Aethos (2021 on) |
|---|---|
| Shell standard | BSA / English threaded (1.37" x 24 TPI) |
| Shell inside diameter | 1.37 in (about 34.8 mm) threaded bore |
| Shell width | 68 mm (road), 73 mm (MTB), 83 mm and 100 mm (fat / DH) |
SHELL 68 mm (road), 73 mm (MTB), 83 mm and 100 mm (fat / DH)
SPINDLE see table
SPINDLE see table
The Specialized Aethos uses a 68 mm BSA threaded shell, unlike the OSBB press-fit Roubaix.
The Aethos is threaded even though other Specialized carbon frames of the era are OSBB press fit. Do not assume OSBB across the range.
The bottom bracket to buy
Search Amazon for BSA / English threaded bottom bracket for your crank spindleaffiliate searchFind BSA / English threaded bottom bracket for your crank spindle on eBayaffiliate
Fit a crank to this shell
BSA / English threaded shell1.37" x 24 TPIShimano Hollowtech II (24 mm) in a BSA / English threaded shelldrops inSRAM DUB (28.99 mm) in a BSA / English threaded shelldrops inSRAM GXP (24/22 mm) in a BSA / English threaded shelldrops inBottom bracket for Specialized Tarmac SL8 (2024 on)also BSA / English threaded
SOURCES: Eminence Cycle Co, WorldTour Road Bike Bottom Bracket Standards 2020-2026 · Park Tool, Bottom Bracket Standards and Terminology · Wheels Manufacturing, BB Overall Width Reference Chart