Some of the new higher end cannondales are coming with PF30 BBs. Maybe a sign of things to come. If one had a BB30 is it possible to use PF30 bearings? As I understand it, a BB30 crank and PF30 crank are the same and only the bearings different. Or is the PF30 shell also different? I know about the FSA universal crank/bearings but was just wondering about "upgrading" a BB30 to PF30.