One if yoo don't need the money why sell the bike; a 15 lb bike still gives you the ride of a 15 lb 6k bike!! As others have said worry about body fat/lean body mass; worry if your cloths aren't geting smaller that is the problem in weight maintance! Also if you are gaining fat; log EVERY THING THAT GOES IN YOUR MOUTH! You will be surprized about the # of Calories you consume vs the # needed to support life sometimes.