Italian threaded bottom bracket shell (36 mm x 24 TPI)
What a Italian threaded shell measures, which crank spindles it hosts, and the bottom bracket to buy.
Published dimensions
| Type | threaded |
|---|---|
| Shell inside diameter | 35 mm threaded bore |
| Shell width | 70 mm |
| Thread | 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 an Italian-thread BB |
SHELL 70 mm
SPINDLE 24 mm (Shimano Hollowtech II), 24/22 mm (SRAM GXP) and 28.99 mm (SRAM DUB) via an Italian-thread BB
SPINDLE 24 mm (Shimano Hollowtech II), 24/22 mm (SRAM GXP) and 28.99 mm (SRAM DUB) via an Italian-thread BB
Used on: older and some current Italian road frames (Colnago, Bianchi, De Rosa).
The trap is the drive-side thread: unlike BSA, an Italian drive-side cup is right-hand and tightens clockwise, so it is more prone to unwinding. A 70 mm Italian shell will not accept a 68 mm BSA BB, the thread pitch and diameter are different.
Fit a crank to this shell
Shimano Hollowtech II (24 mm) in a Italian threaded shelldrops inSRAM DUB (28.99 mm) in a Italian threaded shellnot a simple fitBSA / English threadedrelated shell (1.37" x 24 TPI)
SOURCES: Park Tool, Bottom Bracket Standards and Terminology · The Pro's Closet, Bottom Bracket Identification Guide