Since the OP hasn't responded since making the thread, I think we have enough here. OP rides tall bikes like I do. Getting to 20-21 lbs with steel is tough. How to do it? $$$ of course. Well that and knowledge from research. To do so for an upright city bike....why?

For the record, using an official Park Tool hanging scale (like the one pictured above), I got my 1987 Schwinn Prologue (with pedals and bottle cage) to 18 lb 15 oz. 7900 Dura-Ace for everything, 7850-era super light Dura-Ace wheels. I put all those parts on my 2015 Trek Emonda ALR (aluminum) and it weighs just over 16 lb.