The Sputnik with a carbon fork is a pretty good lightweight frame to start with if it comes stock under 20 lbs. Would make more sense to me to put lighter bits on that than to sell the whole thing and get an entirely different bike when people have builds of this one that come in at 16lbs particularly if you like the bike and the fit. Also pedal wise, plastic BMX platforms are really light iand comfortable if you don't want to go clipless .