There are a lot of things you don't need to buy for your bike, but this state of the art stem cap is not one of those useless things. It was designed with you, yes you, in mind. Molded around the tightest molecular combination of polymers, this stem cap makes you more aerodynamic than a B-2 spirit stealth bomber. Don't know what that is? Look it up. No. Don't waste time. Buy this stem cap and go race down a mountain, or a hill, or your driveway. Who cares? Go ride your bike. Worldwide Cyclery Top Cap Headset Top Cap