on air pressure and a small knurled nut to keep it shut. Inflating a bicycle tire equipped with a Presta or Dunlop valve at an automobile filling station requires an adaptor, while a Schrader-valved tube does not. Inflating at home or on the road requires either 6mm air chuck for Presta and Dunlop valves, or an 8mm chuck for Schrader valves. Some chucks have dual orifices to inflate all three. Dimensions External 8V1 thread: x 32 TPI ( pitch; tap size 8v1-32) Internal 5V1 thread: x 36 TPI ( pitch; tap size 5v1-36) See also Inner tube References External links Schrader-Bridgeport International (North American English version) Vehicle parts Air valves Tires 1891 introductions American inventions fr:Valve Schrader