Adjusting the height of your bicycle's handlebars will make your ride safer and more comfortable. Setting up a bike to fit properly helps avoid fatigue, pain and injury.
1.Examine the bolt at the center of your bike handlebars. Determine whether it has a hexagonal indentation, a bolt that sticks up above the bike stem or bar that attaches handlebars to the bike frame (see Resources).
2. Get on the bike and estimate how much higher or lower you want the handlebars. Choose a height that makes it easy for you to look ahead; don't bend your neck uncomfortably. Preferences will depend on your purpose for riding the bike (racing, touring, mountain biking or casual riding), your skill level, your fitness level and your age (see Resources regarding bike fit).
3. Loosen the bolt with your wrench. You may need to tap the top of the bolt with a rubber mallet to completely free it for adjustment (see Resources for more detailed instructions).
4. Pull up on the handlebars to raise them to your desired height, or push down to lower them. When raising the handlebars, leave at least two inches of the bar inside the bicycle frame; most stems have a maximum height marking.
5. Center the handlebars and the front tire, which will twist when you move the bicycle stem.
6. Tighten the stem bolt with your wrench.
7. Test the fit of your bike, then readjust if necessary.