Mind blowingly simple. And this will be a life saver.
What’s a presta valve?
The valve on the right is a Schrader valve. The Schrader valve is the same valve that’s used on car tires. So a bicycle tube with the Schrader valve can be pumped up at your local gas station if no hand pump (or CO2 cartridge) is available.
The presta valve is on the left. This is typically found in bicycle tubes on many road bikes and some mountain bikes. Since the stem on the presta is a lot narrower, it allows for manufacturers to make narrower wheels and tires. They tend to hold air better than Schrader valves. If you don’t have a bicycle pump that accommodates Presta valves (most allow both nowadays), you could just screw on an adapter and inflate it using the pumps at the gas stations. All you have to do is unscrew the nut to make the presta ready to permit airflow.
So the video up above shows you how to create an impromptu adapter for your presta valve by modifying the valve cap. This way you could pump it using your local gas station or any pump that pumps up Schrader valves.