Groupsets 

Replacing your groupset is something you can do right at home. It's the easiest way of giving your bike a full upgrade or replacing your trusty groupset after years of service. Most groupsets for road bikes use two chainrings these days, allowing you to choose between a compact, supercompact, or classic double. Mountain bikers are seeing less and less double chainrings, as most of them are switching to single chainrings. A triple groupset is becoming increasingly rare on both road and mountain bikes alike.