Bicycle tire pressure refers to the amount of air pressure within the tire. Most tires have a replaceable inner tube that is filled with air, which in turn gives structural integrity to the tire. Tubeless tires hold air without the need for an inner tube. Tire pressure greatly influences the way the bicycle handles on a variety of riding surfaces and is important to maintain for safety reasons. Most tire manufacturers mark the air pressure requirements on the exterior of the tire.
PSI
Like tires on a car or motorcycle, the air pressure in a bicycle tire is measured in pounds per square inch, or PSI. This simply refers to how much pressure, in pounds, the air inside exerts on the tire itself. Manufacturers design tires and their tread pattern to function best within a specific range of PSI based on a maximum load they will be carrying, according to Michelinbicycleusa.com.
Inner Tubes
Inner tubes, by design, withstand an impressive amount of pressure. Tires serve to protect the inner tubes from punctures. In general, filling a tire to a higher pressure results in a harder, less compliant ride. For this reason, many cyclists prefer to fill their tires to a lower PSI to allow for a smoother overall ride, but this increases the chance of rupturing the inner tube.
Tubeless Tires
Tubeless tires require no inner tube because they form an airtight seal directly onto the rim via a bead on the tire and lip on the rim. You pump air directly into the tire instead of an inner tube. Tubeless tires allow cyclists to ride with lower air pressure and without the concern of rupturing a tube. You must maintain a certain minimum amount of air pressure, however, or the tire will not seat properly in the rim. This minimum PSI varies depending on the tire design.
Suggested Tire Pressure
On most good-quality tires, you'll find the tire's specifications imprinted on one or both sidewalls. This information usually includes the size of the tire; for example, "26 inches x 2.1 inches" on a mountain bike tire, indicating the diameter and width, respectively. You may also find an arrow on the sidewall pointing in the direction of intended travel. Also on the sidewall is where you'll find the suggested range of air pressure, marked in PSI. Most mountain bike tires will be in the 40- to 60-pound range, but wider, more rugged tires may call for a lower PSI.
Tire Pressure Characteristics
Tire pressure drastically affects how a bicycle turns, how far and fast it rolls and how it reacts to bumps on the riding surface. The higher the tire pressure, the faster the bike will ride, but you'll be sacrificing some traction. A tire's tread by design planes to some degree, providing a flat surface to securely grip the road or trail, according to Sheldonbrown.com. At the same time, air pressure pushes outward to the sides of the tire, making it able to withstand the weight of the rider. Many off-road or touring riders may prefer a slightly lower PSI, while more aggressive road cyclists and commuters may choose a higher PSI.
Member Comments