What bottom bracket does a Cannondale SystemSix use?
The bottom bracket shell standard on a Cannondale SystemSix, and how to pick the right BB.
This frame's shell
| Frame | Cannondale SystemSix |
|---|---|
| Shell standard | PF30A press fit (Cannondale Ai) (46 mm bore, 73 mm asymmetric) |
| Shell inside diameter | 46 mm smooth press-fit bore |
| Shell width | 73 mm (asymmetric, for Cannondale Ai offset rear) |
SHELL 73 mm (asymmetric, for Cannondale Ai offset rear)
SPINDLE see table
SPINDLE see table
The Cannondale SystemSix Hi-Mod uses PF30A, a 46 mm press-fit bore in a 73 mm asymmetric shell for the Ai offset rear.
Standard SystemSix builds use BB30A and Hi-Mod builds use PF30A. Confirm the bore (42 mm versus 46 mm) before buying.
The bottom bracket to buy
Search Amazon for PF30A press fit (Cannondale Ai) bottom bracket for your crank spindleaffiliate searchFind PF30A press fit (Cannondale Ai) bottom bracket for your crank spindle on eBayaffiliate
Fit a crank to this shell
PF30A press fit (Cannondale Ai) shell46 mm bore, 73 mm asymmetric30 mm spindle (BB30 / PF30 style) in a PF30A press fit (Cannondale Ai) shelldrops inShimano Hollowtech II (24 mm) in a PF30A press fit (Cannondale Ai) shellneeds a reducerBottom bracket for Specialized Tarmac SL7 (2021 to 2023)related shell
SOURCES: Hambini Engineering, Specialized OSBB Engineering Guide · Wheels Manufacturing, Cannondale BB30a & PF30a Bottom Bracket Guide · BikeRadar, The complete guide to bottom bracket standards · Wheels Manufacturing, Three Common Bottom Bracket Misconceptions