Originally Posted by
milesofsmiles
I am quoting myself from post
#4 . Actually it's more like 5' 9.5". I just checked and I have 2"-3" of but...... , this is my type of frame. It angles downward toward the seat and then has another short bar that angles up about 3" from the frame to the top of the seat tube so I guess that rule isn't written in stone. Actually I think it makes the frame look cooler this way. It has rear suspension too, I don't know if that's why they designed it this way.
Mountain bike frames have different rules.
The idea is to get the top tube as low as possible to allow the rider room to move around while riding through rough ground, jumping, etc.
This is part of the reason mtb seatposts are so long. The short bar that angles up is to stiffen/strengthen the seat tube where it joins the post.