Bike upgrades

shoes/pedals

aero bars

these two are first they will increase your power to the bike, and lower your resistance. then i think its a matter of personal situation. maybe your weels are good and you have low components... then you would go with companents.

well if you don't have pedals and clipless shoes then you should get some. the next thing you do if you have a little cash is go out and buy yourself some GOOD wheels. But it's all about your budget, if you have 2k laying around a zipp 909 wheelset is in order. If you have 500 dollars laying around a pair of Kysyrium Elites (I wouldn't upgrade my wheels unless I have at LEAST 500 to spend on it). But wheels should definitely come before componenets, they make a big difference. Why...because rotational mass on a bike is equivalent to stationary mass 4 times it's weight. For example .5 pounds of rotational mass is equal to aobut 2 pounds of stationary mass. if your on a tight budget aerobars also help. Don't forget the main componenet is the engine.