Been doing alot of research for new bike. From what I can see most bikes are equipped with shimano 105 groupset and 50/34 some 52 or 53 teeth. Wheelset usually shimano rs wheels. My current bike has 50/34 full carbon weighs 9kg with 105 groupset and stock wheels. I need a 2nd bike for my weekend spins to make it more enjoyable thn it is and easier to take the front on group rides.What is the diff too a bike with the same 105 groupset and weighing 7kg or even the ultraegra parts? Is it all to waste your money? Please excuse my ignorance.