frame size
 

I have one road bike is 56cm seat tube and top tube is 55cm. Because the stem is was short i put one stem i have 125mm. Now i see even the wheel hub when i am in the dropouts. The stem looks too long. If i had use 110 mm stem that means i need longer top tube like 56cm? I not have ride the bike yet for i can see how i go feel with that long stem. How i calculate torso and arm length for i see what length top tube is good for me.