I have a Cannondale PF30a frame (assymetric 73mm by 46mm cup).
It came with a standard FSA internal bearing BB without any spacers, so the overbearing width measures maybe around 75mm with seals. That will not work with any modern spindles and must have been for some old Cannondale short spindle Hollowgram crankset.
I had to buy a wider BB. There are plenty of outboard (bearings out of the frame) 30mm BBs, but the measure something around 73+13+13 = 99mm overbearing width with seals or similar. The problem is that to achieve a proper chainline and clearances 13mm driveside clearance may not be enough and I may need some spacers. Which makes it even wider.
My Praxis Doon crankset has a pretty standard 107mm overall spindle length.
Between Cannondale, Praxis, Wheels Manufacturing no one is able to give any dimensions, it seems to be a simple basic information but they are useless...
Question: is there any standard on the engagement depth of a standard splined two piece crankset? I am trying to understand if the crankset will be long enough to fit into an outboard 73mm PF30 BB.
Of course, there is an option of a specific PF30a BB, which has one outboard and one internal bearing (i.e. it is assymetric as well). But ideally I would prefer the maximum spacing between the bearings and not to use too many spacers.
It came with a standard FSA internal bearing BB without any spacers, so the overbearing width measures maybe around 75mm with seals. That will not work with any modern spindles and must have been for some old Cannondale short spindle Hollowgram crankset.
I had to buy a wider BB. There are plenty of outboard (bearings out of the frame) 30mm BBs, but the measure something around 73+13+13 = 99mm overbearing width with seals or similar. The problem is that to achieve a proper chainline and clearances 13mm driveside clearance may not be enough and I may need some spacers. Which makes it even wider.
My Praxis Doon crankset has a pretty standard 107mm overall spindle length.
Between Cannondale, Praxis, Wheels Manufacturing no one is able to give any dimensions, it seems to be a simple basic information but they are useless...
Question: is there any standard on the engagement depth of a standard splined two piece crankset? I am trying to understand if the crankset will be long enough to fit into an outboard 73mm PF30 BB.
Of course, there is an option of a specific PF30a BB, which has one outboard and one internal bearing (i.e. it is assymetric as well). But ideally I would prefer the maximum spacing between the bearings and not to use too many spacers.