Outdoor public air compressor for bikers in Linköping, Sweden.
A bicycle pump is a type of positive-displacement pump specifically designed for inflating bicycle tires. It has a connection or adapter for use with one or both of the two most common types of valves used on bicycles, Schrader or Presta. A third type of valve called the Woods valve exists, but tubes with these valves can be filled using a Presta pump.[1]
Several basic types are available:
Floor models or track pumps
Frame mounted
Compact or mini
Foot operated
Double action
In its most basic form, a bicycle pump functions via a hand-operated piston. During the up-stroke, this piston draws air through a one-way valve into the pump from the outside. During the down-stroke, the piston then displaces the air from the pump into the bicycle tire. Most floor pumps, also commonly called track pumps, have a built in pressure gauge to indicate tire pressure.
Caution must be used when using a gas station air pump. Some are designed to cut off before the high pressures used in many bicycle tires are reached. Other operate at such a high pressure that the tire can be burst. There is also a slight difference between the modern standard for Schrader valves on an automobile and that on a bicycle which makes some more recent valves on gas station pumps a poor fit.