Presta valves are skinny (6mm in diameter) needle-like inner tube valves you’ll discover on basically all road bikes and more expensive mountain bikes. The Schrader is the standard valve you discover on motor vehicle tires and a lot of bicycle internal tubes. The normal Presta valve has an external thread. https://webookmarks.com/story5298105/how-much-you-need-to-expect-you-ll-pay-for-a-good-presta-addons