Bike Tire Valves

tire valves
(Tire valve) The fitting in the valve stem of the wheel that allows you to inflate or deflate the tire.
A valve stem is a self-contained valve which opens to admit gas to a chamber (such as air to inflate a tire), and is then automatically closed and kept sealed by the pressure in the chamber, or a spring, or both, to prevent the gas from escaping.

bike
A bicycle or motorcycle
bicycle: a wheeled vehicle that has two wheels and is moved by foot pedals
motorcycle: a motor vehicle with two wheels and a strong frame
bicycle: ride a bicycle