Slow Leaks
Check your bicycle tires for slow leaks any time you've stored your bicycle for long periods of time. It's normal for inner tubes to lose air while your bike is stored in the garage over the winter. If your tires lose more than a little air during the week, it may be time to consider replacing the inner tubes.
Punctures
Replace your inner tubes anytime you run over a nail, thorn or piece of glass. If you can't find anything sharp that has punctured your inner tube, inspect the inside of the wheel rim. The end of a tire spoke may have punctured the inner tube. Replace or repair the spoke before repairing the flat.
Pinch Cuts
Repair the inner tube if you have run over a pothole, a curb or sharp stone. Running over large objects can cause pinch cuts. Pinch cuts result when the inner tube has been pinched between an object and the inside of the rim.
Blowouts
Install a new inner tube (and possibly a new tire) whenever you experience a blowout. Blowouts are sudden losses of air pressure that occur when there are weak areas in the tube. They may also happen if there is a weak area in the sidewall of the tire.
Article Written By Allen Smith
Allen Smith is an award-winning freelance writer living in Vail, Colo. He writes about health, fitness and outdoor sports. Smith has a master's degree in exercise physiology and an exercise specialist certification with the American College of Sports Medicine at San Diego State University.