The Tour de France is coming soon (July 4th in fact). I invite you to watch closely. Watch the riders’ positions on their bikes, especially when the moto-cam is moving parallel with the racers. Look at the angles of their backs, arms, leg extension, etc.. You’ll be surprised at the variety of riding positions. Most are pretty biomechanically sound, but a surprising number are just plain weird looking on their bikes. By "wierd" I mean less efficient, less stable and less comfortable than they could be.
Sean Kelly won many races despite a notoriously bad bicycle fit. Imagine how many more he would have won if his bikes had been properly adjusted for him.
Many European bicycle racers still use traditional (AKA "mimic the old pros") methods for setting up their bikes. Sometimes the racer is just following orders from team management. Many times they’re simply doing what they’ve been doing since they started cycling seriously, in other words, not stopping to analyze their bike set-up. Modern research has proven many of those "traditional" methods are just plain wrong. They frequently produce lower performance and sometimes even produce injury.
I recall watching Frank Schleck win atop Alpe d’Huez. His knees were traveling side to side at least half a foot with every pedal stroke. The fact he won while wasting such an incredible amount of muscle energy made it all the more astounding he won. He’s had a proper bicycle fitting since then and specifically addressed his knee "problem." Watch out for him in the mountains even more, now.
My point is that, if we find experienced Pros riding poorly fitted bikes, it’s pretty silly when recreational riders convince themselves they can find their optimal bicycle set-up through trial and error based on no training in the science of bicycle fitting.