Shell BSA vs Shell Italian: specs compared
Updated 05 September 2026.
4
specs differ
Shell BSA and Shell Italian differ on 4 specs: shell inside diameter, shell width, thread, crank spindles it hosts.
| Spec | Shell BSA | Shell Italian |
|---|---|---|
| Type | threaded | threaded |
| Shell inside diameter | 1.37 in (about 34.8 mm) threaded bore | 35 mm threaded bore |
| Shell width | 68 mm (road), 73 mm (MTB), 83 mm and 100 mm (fat / DH) | 70 mm |
| Thread | 1.37 in x 24 TPI, drive-side cup left-hand (reverse) thread, non-drive right-hand | 36 mm x 24 TPI, both cups right-hand thread |
| Crank spindles it hosts | 24 mm (Shimano Hollowtech II), 24/22 mm (SRAM GXP) and 28.99 mm (SRAM DUB) via the matching threaded BB | 24 mm (Shimano Hollowtech II), 24/22 mm (SRAM GXP) and 28.99 mm (SRAM DUB) via an Italian-thread BB |
Questions and answers
How do Shell BSA and Shell Italian compare?
Shell BSA and Shell Italian differ on 4 specs: shell inside diameter, shell width, thread, crank spindles it hosts.