Bicycle tyre valves allow riders to inflate their tyres with air. According to bicycle expert Sheldon Brown, the three types of bicycle tyre valves are Schrader, Presta and Woods. Cycling writer Jobst Brandt says most current bicycle manufacturers produce Schrader and Presta valve tubes. Most bicycle valves attach permanently to inner tubes, but some newer tubeless bicycle tyres use a special Presta valve temporarily attached to the wheel rim.
Also called "American valves," Schrader valves have a simple tubular shape with a central pin. Dominant in the USA, they are also common in Britain. Most children’s bicycles and other less expensive bicycles use Schrader valve tubes.
Presta valves, or "French valves," are thinnerr than Schrader valves and use a locknut mechanism to retain air pressure. Presta valves require a Presta pump or a Presta valve adaptor, which you can find at bike shops. Presta valve caps protect a tube from valve puncture during shipping, but Brown's Bicycle Glossary says riders don't need to use caps.
Woods valves, roughly the size of Schrader valves at the base, taper to the size of Presta valve locknuts. Once common in Asia and the British Isles, Woods valves are now rare. Presta pumps work with Woods valves. The rubber interiors of Woods valves deteriorate over time so they no longer retain air. Some patch kits include short lengths of rubber tubing designed as replacement rubber interiors for Woods valves, according to Brown's Bicycle Glossary.