To inflate a Presta valve, you just unscrew the valve stem anti-clockwise after which attach a pump. The moment the desired air strain is achieved, remove the pump and screw the valve stem clockwise to make sure it's airtight. Some pumps, like this Silca Gravelero, element reversible chuck heads. - https://tripsbookmarks.com/story19779274/the-single-best-strategy-to-use-for-presta-addons