Bicycle tubes are usually equipped with one of two types of valves: Schrader valves and Presta valves. Schrader valves are more common and recognised, being widely used in car, motorcycle and bicycle tires and tubes. Presta valves are more commonly found in road and track bicycles that have narrow rims that cannot accommodate the size of a Schrader valve. Presta valves have a locking nut, rather than a spring, that allows air in and out of the tire. Knowing how to pump up Presta valve tires and tubes is critical for proper bicycle safety and performance.
Remove the plastic Presta valve cap. Some valves do not have a protective cap. If yours does not, proceed to Step 2.
Loosen the locknut on the Presta valve by turning it counter clockwise. Do not completely remove the locknut.
Secure your bicycle pump to the open Presta valve. Most pumps have a thumb lever on the head of the pump that can be locked onto the valve.
Inflate the tire with the pump to the desired pressure, checking the pressure periodically with your tire pressure gauge.
Unlock the pump's lever and remove the pump.
Tighten the Presta valve locknut by turning it clockwise. Do not overtighten the locknut.
Replace the plastic Presta valve cover, if available.
Many pumps work with both Schrader and Presta valves, requiring a simple changes made on the inside of the pump head. Refer to your pump's manual for instructions on how to convert your pump. If you do not have a plastic Presta valve cover, consider investing in some. Covers protect valves from moisture and dirt, prolonging the life of your Presta valve. Invest in a Presta-Schader valve adaptor, which will allow you to use Schrader pumps on your Presta valve, when Presta pumps are not available.
Never overtighten the lock nut--finger tightening should be sufficient. Do not over- or under-inflate your tire as it may result in poor or dangerous handling.