Скачать с ютуб How a Presta Valve works on a Road Bike в хорошем качестве

How a Presta Valve works on a Road Bike

Presta valves on road bikes: How they work. Presta valves are very popular on road bikes, especially high-end bikes, and those with narrow rims. Unlike the Schrader valve, Presta valves rely on pressure inside the tube or tire to close. Schrader valves use an internal spring to automatically close the valve whether there is pressure inside the tube or not.