A Cannondale F-Si (BB30A) frame uses a BB30A press fit (Cannondale) bottom bracket shell (42 mm bore, 73 mm asymmetric). The dimensions, which cranks fit, and the exact bottom bracket to buy.
Updated 05 September 2026.
What bottom bracket does a Cannondale F-Si (BB30A) use?
The bottom bracket shell standard on a Cannondale F-Si (BB30A), and how to pick the right BB.
| Frame | Cannondale F-Si (BB30A) |
|---|---|
| Shell standard | BB30A press fit (Cannondale) (42 mm bore, 73 mm asymmetric) |
| Shell inside diameter | 42 mm smooth press-fit bore |
| Shell width | 73 mm (asymmetric, 5 mm wider on the non-drive side) |
SPINDLE see table
The Cannondale F-Si (BB30A) uses a BB30A press fit (Cannondale) bottom bracket shell (42 mm bore, 73 mm asymmetric), a 42 mm smooth press-fit bore, 73 mm (asymmetric, 5 mm wider on the non-drive side) wide.
It is a press-fit shell, so bearings or cups press into the 42 mm smooth press-fit bore. Match the shell width as well as the bore, because a shorter unit will not preload the crank across a wider shell.
SOURCES: Wheels Manufacturing, Cannondale BB30a & PF30a Bottom Bracket Guide · Kogel Bearings, Cannondale BB30A and PF30A explained
Questions and answers
What bottom bracket does a Cannondale F-Si (BB30A) use?
A Cannondale F-Si (BB30A) frame uses a BB30A press fit (Cannondale) bottom bracket shell (42 mm bore, 73 mm asymmetric).