Originally Posted by
Campag4life
You made a real generic claim tfp. For veracity, you will have to be quite specific. Quite possible we aren't even talking about the same thing and speaking right past one another. All PF/BB30 bottom brackets are flush by design. Spacing the crank away from the frame may vary. Depends on the crank. Some 30mm long spindle cranks will be spaced well away from the frame like Rotor with a regular PF30 BB with bearings within the shell.
Again, your statement that ALL BB30 cranks are flush by design is inaccurate. Some are. Some aren't. It depends on the crank.
Cannondale, at some point, switched from a 104mm spindle to a 109mm spindle to accommodate the BB30A system. If you put one of those BB30A spindles on a BB30 frame, you will need a spacer to fill the gap between the NDS crank arm and the frame.
See here:
https://www.cannondaleexperts.com/Ca...83_p_5630.html
And here:
https://www.cannondale.com/~/media/F...nstr_1012.ashx
Also, Sram requires spacers and pre-load adjusters on some BB30 cranks (those with carbon arms and removable spiders), which space the arm from the frame:
https://www.sram.com/sites/default/f...brackets_0.pdf
The full carbon Sram BB30 cranks, like Sram Red, are flush with the frames.