Thanks, and that makes sense. What is still very unclear is which models have the carbon osbb that is 61x46 and needs press in cups, and which have the alloy osbb that is 68x42 and requires circlips. Specialized seem to have conflicting documents as to which my frame (2011 tarmac sl3 pro (sram)) has. Is there an easy way to determine this, specifically while the current specialized crank is installed?
I think I have now come to the conclusion that a bb30 crank (rotor 3d+ power2max) is the correct option, but want to make sure I have or order the correct clips, cups, etc. Is it the case that I can just use the cups or clips that are on the current specialized crankset, or is it best to start fresh?
Also along those lines, although I am not experiencing any issues with my original bb, when I go to install the new crank, is it a good idea to do a new bb/bearings? My bb is original and has roughly 20,000mi on it, has been cleaned/greased periodically, and seems to still spin smooth, but I'm not finding very clear information on typical bearing life span, and am thinking that if the degradation of the bearings happens over such a long period of time I may not necessarily know that they are that worn until I feel new bearings.
Thanks for your help, I'm probably over thinking some of this, but just want to make sure I do this right.