2012 regulation

FROM TUBELESS TO TPMS

Over the past years, there has been a strong increase in the demand for electronic equipments to assist driving and security. Tyre pressure is an important security element because it impacts the way the car holds the road. In 2000, American legislation (TREAD Act) obliged all the car manufacturers to equip the new vehicles with a system to inform the driver if a tyre is not inflated enough. If a tyre is under-inflated, the fuel consumption goes up to 6%. Considering this fact, European Commission has just decided to make this system compulsory from November 1st, 2012.

Schrader had anticipated this demand by offering in 1999 already equipment called TPMS, meaning « Tyre Pressure Monitoring System ». The idea is to associate to the valve an electronic box, which is able to measure and to send through radio wave the state of pressure and temperature of each tyre. There are 2 advantages to associate the box to the valve. It gives it a good fixing and it uses the valve as an antenna to send out the signal outside the tyre. Finally, this system does not add any sealing zone between the rim and the tyre and it uses the valve to get attached.

The rubber « snap-in » tubeless valves allow a fast mounting. For high-speed applications, the use of metal « clamp-in » valves is recommended which warranty a better resistance to high pressure. On the other hand, « clamp-in » valves are more demanding for the user than « Snap-in » valves, because it is necessary to respect the core torque requested when the seal is changed and to use various components (nut, seal, seat…)

Schrader reminds that for each change of tyre: The « snap-in » valve must be changed (the electronic box is used again). The metal clamp-in valve seal must be changed with care by respecting the torque requested for the nut and the core during the mounting.