Definitions for "Presta valve"
Keywords:  unscrewed, bicycle, bike, valve, tire
A type of valve located on your tire where you put in the air. A Presta valve is the skinny type, and has to be loosened by hand before the air is put in.
type of air valve used on high performance, narrow, roadie wheels. Uses a locknut instead of a return spring to keep valve closed. Although these valves are smaller, lighter and make less of a hole in the rim they are still annoying because getting air from a conventional source (gas station) requires a stupid little adapter.
the narrow valve found on most mountain bike inner tubes. A metal cap must be unscrewed before air can enter or exit.