If you've just bought yourself a new aero bike, then you'll probably want a wheelset with an aerodynamic edge. These are wheels that have extra material extending down from the rim, which helps the rim cut through the wind. They can give a real advantage if you're racing, or if you want to improve your average speed on your rides. It's worth bearing in mind, though, that to get the most aerodynamic benefits you need to be consistently travelling above 32kph. Of course, if you want a deep section wheel with a carbon build you're going to be spending a fair whack. You can get cheaper, aluminium builds but these tend to be a bit heavier.