You are right about making a bigger problem out of something that is pretty trivia, sorry about that. After all the searching and studying, (I am an aerospace design engineer by trade and am a big consumer of data, facts and specs), I have decided that I will go out and find the right size Trek 520 Disc. Unfortunately it will still be a while before I can start doing any serious riding as my wife is terminally ill and I am her 24/7 caretaker, not complaining but my bike riding, working out, etc continues on hold for now. The best I can do is start planning for something fun that I can look forward to when this is all over. Anyway, I will try not to ask any more stupid questions.