How to Pump Up Your Tires (Both Presta and Schrader Valves)
Putting air in your tires is a simple, often overlooked part of bicycle maintenance. However, it can take you by surprise if you are fairly new to the cycling world.
It's also very important to keep your tires properly inflated. Failure to do so will cause poor handling and excessive tire wear, both of which could lead to a crash.
You are probably used to Schrader valves, which are the big, fat valves just like on car tires. Some bikes have these, and in that case, any tire pump will inflate your tires.
The basic procedure is to press the pump's nozzle onto the valve and start pumping. Then remove the nozzle when the tire is inflated.
Things are slightly trickier when your bike has Presta valves, which are taller and skinnier than Schrader valves. (These are usually found on more expensive bikes.)
In this situation, you actually need a bicycle-specific tire pump that is made for both valve types. (These are available at any bike shop or online bicycle retailer.
To work with a Presta valve, first you unscrew the little nut at the top of the valve, which will let air in and out.
Then press the pump's nozzle onto the valve, flip the lever to lock it on, and pump. Once the tire is inflated, flip the lever down, remove the nozzle, then screw the nut back down to close the valve.
Remember to keep your tires inflated to the recommended pressure (which is usually printed on the tire's sidewall for easy reference.) You should check the pressure at least once per week.
Now you know how to pump up a Presta valve and a Schrader valve.