Nothing amps up your ride like a wheel upgrade, and Shimano's RS21-CL wheelset is well worth a look. With a respectably low weight and double-butted aero spokes, these hoops are durable enough to train on and light enough for race day. The wide hub flanges and asymmetric rear rim keeps them stiff—just what you need for steering precision, high-speed cornering, and efficient power transfer. And, Shimano's angular contact bearings offer miles and miles of smooth-spinning, low maintenance riding. They're also compatible with 8-, 9-, 10- and 11-speed cassettes so you can use them on all your bikes.