Originally Posted by rpenmanparker

Maybe I didn't make it clear enough. I did not mean that most bike makers list effective seat tube as a measurement in their geometry chart. I meant that their size numbers at the top of the column closely relate to the EST. So a size 54 Tarmac roughly has a 54 cm EST. With BD and a few others the situation is different. In those cases the size number at the top of the column closely relate to the actual seat tube length. That is the difference that causes confusion. Neither number should be the be all and end all of bike choosing and bike fitting. But the difference does explain why two companies whose bikes would fit similarly call them different sizes. And in case anyone remembers, that is all I was trying to inform OP of in the first place.