28. How to Use a Presta Valve Adapter
Learn how to use a presta valve adapter to inflate your tire using a regular air pump.
The two most common valve types these days are Presta valves and Schrader valves. Schrader valves are most commonly found on bikes with wide rims and are the same style you'll find on most automobiles. They use an internal spring to allow inflation while keeping the valve closed. You can inflate this style easily with any regular air pump.
Presta valves are a lot narrower and are commonly found on higher end bikes with narrow rims. They are a little trickier to inflate as they use a manual locknut to open the valve for inflation. To inflate a Presta valve you'll need a regular air pump and a special adapter. These can be purchased for about a dollar at your local bike shop. In this tutorial, we'll learn how to use the adapter to inflate your tire.
The first step is to remove the cap and then loosen the valve's locknut all the way counter-clockwise. Notice that you can now let air out by depressing the locknut.
Now install the adapter by carefully threading it clockwise onto the valve stem's threads. The adapter effectively converts your Presta valve to a Schrader valve so that you can use a traditional air pump to inflate it. Attach your air pump and inflate the tire to the recommended pressure. This is written on your sidewall and is usually marked with a 'PSI' rating (pounds per square inch).
Once the tire is fully inflated, remove the air pump, remove the adapter, and finger tighten the locknut. Then replace the cap. There is another locknut at the bottom of the valve stem. This should be finger-tightened once the tire is inflated.