Valve

• Which is the best valve?
• What causes valve tear off?

Which is the best valve?

There are three types that have become market standards and it is difficult to make any particular recommendation. The most important aspect is that the valve fits the rim valve hole and that an appropriate pump is available.

Contrary to popular belief, major air retention differences are now a thing of the past. In any event, SCHWALBE valves certainly provide excellent performance and are adapted to high-pressure use.

The traditional bicycle valve or Dunlop valve is still the most common worldwide and most cyclists are familiar with it.

The valve core is easily replaced and the air can be released very quickly.

Fitting a tube with a Dunlop valve is more awkward, as the valve core and locknut need to be removed in order to fit the valve through the valve hole. Inflation is only possible once the core and the nut are back in place.

With traditional Dunlop valves, it is impossible to check the inflation pressure. However, the special SCHWALBE Dunlop valve allows a return airflow, so that it is now possible to check the inflation pressure with an AIRMAX pressure gauge.

In former times it was difficult to inflate a tube with a Dunlop valves, but with today’s modern valve cores, this is no longer the case.

The Sclaverand valve at 6 mm instead of 8 mm is much smaller than other valves, requires a smaller valve hole and so is very well suited for racing bicycle rims.

It is also 4 - 5 g lighter than a car valve or Dunlop valve.

The top nut can be turned by hand and has to be opened before inflation, which surprises many first-time users. Also the thin top pin can be bent easily when attaching and removing the pump connector.

Be warned that using Sclaverand valves tubes on rims with larger valve holes often leads to valves shearing off when the sharp metal edges around the valve hole cut the valve stem off the tube.

The auto valve is becoming increasingly popular as it can easily be inflated at service stations and is very user friendly.

Older, as well as simple bicycle pumps are not compatible with auto valves.

The Regina valve looks very much like the French valve and is used almost exclusively in Italy.

What causes valve tear off?

A valve can be torn off if it has been installed under tension.

Another frequent cause is installing a Sclaverand valve tube into a rim with a larger valve hole. The metal edge of the valve hole can shear the valve stem off the tube.

Be aware that there are also rims around that have the correct valve hole of 6.5 mm on the outside, but a larger hole of 8.5 mm on the inside, which causes the problem.

The rim nut should only be tightened lightly by hand. A nut that is tightened excessively just exacerbates the problem of tear off. The major role of the rim nut is to lock the valve in place at the time of inflation.

Torn off valves are often seen on mountain bikes. Continually improving brake performance and low inflation pressures often cause tires to slip on the rim. The tube is then dragged by the tire movement and this can lead to the valve shearing off. In order to prevent this from happening we developed LIMITED SLIP TECHNOLOGY (LST) used on our mountain bike tires. The tire bead is coated with a special rubber layer that produces a dramatic reduction in tire/rim slip.