How to Fill a Racing Bike Tire
By Rocco Pendola

Racing bike tires most often use an inner tube that contains a Presta valve.
The Presta valve is commonly referred to as the "skinny" valve.
It's the opposite of the Schrader valve, which is exactly like the type found on a car tire.
While it confuses some cyclists, there is no need for alarm when you encounter a Presta valve.

1 Remove the valve cap if your Presta valve has one.
The valve cap, often black, is the plastic piece that screws on over your inner tube's valve to protect it.

2 Unscrew the tip of your Presta valve, by turning it in a clockwise direction.
Opening up the valve like this allows air to enter or escape the tube.

3 Place the nozzle of a bicycle air pump onto the Presta valve.
Use enough force to create a secure connection, but do not push too hard.
Getting this right can require a little bit of practice -- generally just a few tries before you master it.
Most newer model bicycle pumps work right out of the box on Presta valves.
Some require that you flip a lever or unscrew the nozzle and flip over the fitting
inside of the nozzle to switch between Presta-valve and Schrader-valve compatibility.

4 Pull the lever on the pump's nozzle up with your thumb after you have it secured to the Presta valve.
Pump your tire up to the pounds per square inch (PSI) recommended by your tire's manufacturer.
The manufacturer usually includes a PSI range on the tire's sidewall.
Generally, racing bike tires require between 100 and 130 PSI.
Most new pumps include a built-in gauge.
If yours doesn't, you might need to use a separate PSI gauge, available at most bike shops.

5 Use your thumb to push the nozzle's lever back down.
Concurrently, pull the nozzle off of the Presta valve.

6 Tighten the Presta valve's tip by turning it in a counterclockwise direction.
Replace the valve stem cap, if applicable.