Cycling components can upgrade and improve your bike from the way it came from the factory or to replace worn out bike components. For a performance and efficiency standpoint nothing can improve a bike easier than a new set of wheels. Dollar for dollar, replacing the large rotational mass of your bike with something lighter and stronger will breathe life into an older bike.
Bike pedals and saddles can both improve your performance on the bike, as well as your comfort. A new set of clipless pedals and introduce you to the world of full circle pedaling and a new saddle can help get you into a position of increased biking comfort and more power.
Bike grip tape and aerobars can improve the touch points on your bike. Numb hands or wanting to be more aerodynamic can be simple improvements with new bar tape or clip on aerobars. Cool new colors and styles of bike bar tape can also add a new touch of flair to your bike!