To inflate a Presta valve, you simply unscrew the valve stem anti-clockwise and afterwards attach a pump. When the specified air strain is attained, take out the pump and screw the valve stem clockwise to make certain it is airtight. Some pumps, like this Silca Gravelero, attribute reversible chuck heads. https://reallivesocial.com/story5326100/prestashop-addons-options