A "clincher" is the most common type of rim used on bicycle wheels. Clincher bicycle rims are similar to automobile rims in terms of how the tire adheres by means of a ridge on the inside of the rim that "clinches" a bead running along the inside of the tire.
How a Clincher Works
A clincher bicycle wheel "clinches" the tire by means of a ridge on the inside of the wheel rim. When the tire is properly mounted on the rim, beads made from wire or other strong material along the inside of the tire seal snugly against the ridges inside the rim. When the tire is mounted on the wheel rim and properly inflated, it holds firmly in place without shifting or moving.
Aside from the frame, nothing adds more to the safety and performance of a bike than the wheels and tires. A well-built set of wheels fitted with properly sized and inflated tires is the best assurance of safe, easy-rolling rides. On the other hand, poorly designed wheels, low-quality tires or improperly inflated tires can destroy the quality of the ride and also cause serious safety problems.
Wheels, tires and tubes must always be in tip-top shape to avoid trouble on the road or trail. There's nothing worse than having an accident because of poorly functioning wheels or an avoidable blowout because of poor-quality or improperly maintained tires and tubes. To avoid this problem, check your wheels and tires for proper functioning before every ride. Look closely at the outside surface of your tires, and clear any debris that might be stuck in them; these can cause flats while riding. In addition, replace your tires and tubes when damaged or at least once a year.
Tires and tubes
The vast majority of clincher bicycle wheels require tubes inside the tires. Always buy quality tubes and tires from a reliable source, such as your bike shop and make sure the tubes and tires you purchase are the proper size for your clincher wheel to ensure reliability and performance. Also make sure the tires are inflated to the proper pressure, which is indicated on the sidewall of the tire. Because of recent technological advances, some clincher bike wheels do not require tubes inside the tires.
Clinchers Versus Tubulars
Although the clincher-type wheel is the most common design for all bike styles, another type of wheel is sometimes used. Many road and cyclocross racers prefer to ride "tubular," or "sew-up," wheels and tires for best performance and reliability in extreme racing conditions. A tubular wheel requires the tire (in which the tube is pre-inserted and completely enclosed inside the tire material) to be glued onto the rim. One of the greatest advantages of tubular wheels is their rims, which are just as strong though much lighter than clincher rims.