Just how important are Rubber Tyre Valve Stems? Very! So what are they? They are a low priced 50 cent rubber part which controls the entry and exit of air from a wheel. A leaking tyre valve can result in inconvenience and a damaged tyre and sudden failure can have catastrophic consequences including injury or death.
Basically there are two types of tyre valves, metal and rubber. Metal valve stems have different performance characteristics to those made of rubber. They can leak if their retaining nuts work loose which, largely due to operator error, can occur during tyre changes. They tend to have a longer service life and are much more expensive than the rubber alternative but are probably less prone to catastrophic failure. They are not suited to fitment on all wheels.
Rubber valve stems are the most widely used product, are low cost and highly effective when installed properly and in good condition. However, problems arise when a valve stem had been incorrectly fitted by a careless or poorly trained operator; they must be seated firmly but not so firmly that they are stressed or almost pulled out the other side. Careless or poorly trained operators can damage valve stems when doing puncture repairs or fitting new tyres. The valve stems can get crushed/stressed and start leaking straight away or a short time later. Often new tyres are fitted without problems and the customer drives away only to “get a puncture” a few days later. Actually it is a loss of air due to a damaged valve stem and the driver may only discover this after the tyre has been ruined. New stems have good resistance but older valve stems are highly susceptible to damage. It is important to note that Rubber Valve stems deteriorate with age.
There has been a lot of controversy in the United States about the quality of Chinese stems compared to those made in the USA. In New Zealand most stems are imported from China and Bettertyres has no concerns about this; our concerns being operator training and age of valve stem.
Given that Tyre Valve stems are generally at their oldest by the time new tyres need to be fitted to a vehicle, the Campaign for Bettertyres strongly recommends that new Rubber Valve Stems are installed every time new tyres are fitted.