Maybe I should try to clarify this another way... If you are at the track and a rider says to you... " man, my 11inch just isnt high enough for this track" ...he is referring to his BB height. he would not say " man, my 55 is too low"
hope that works!
DW Yes, you are right in the drop issue, but track racers dont refer to it as drop. They all use BB height as their standard measurment.