I have been watching this video: http://bicycletutor.com/adjust-seat/ In it he says that a guide to if the saddle is to far forward or back is when my lower leg is vertical above the pedal when the ball of my foot is on the pedal. I hav emy saddle moved as far forward as possible. When the middle of my foot is on the peddal my lower leg is straight, but with the ball of the foot on the pedal my lower leg is at an angle to the vertical line above the pedal. The height & angle of the saddle are fine. In order to get my lower leg in the vertical position like he says in the video, with the ball of my foot on the pedal, I have to slide right back on the saddle (almost off it).....then I am totally stretched and this leads me to think that I need a shorter stem perhaps....and adds to my belief that the LBS sold me a frame size to far. I looked at my stem ...erm...the one on the bike...and the only indication stamped on it said: H612A...so is this a size code or something? ..any thoughts?