A single other point not described is cable drag. The cable routing of some bikes is such as Gordian Knot (mentioning no names, Nonetheless they talk Canadian French to aero obsessives, One more tends to make pretty, pretty huge bikes & throws them & worst of the many 'really rated' https://rowanujbpf.blogacep.com/38054556/the-fact-about-indexing-bike-gears-that-no-one-is-suggesting