sometimes referred to as “High Pressure” or “Sclaverand” is a high pressure valve capable of the holding the high pressures needed in racing bike tyres. The valve shaft is a narrower diameter (6mm) and the valve is typically lighter than Auto or Dunlop/Woods valves. The valve is released by undoing a small thumblock nut and pressing the release pin. Once inflated, the valve should be locked by tightening the lthumblock nut again. Presta valves are available in different lengths to suit many of the modern deeper bicycle rims. Presta valves should not be fitted to a rim which is drilled for Auto or Traditional valves as this may result in the valve being ripped out of the tube.