Tyron bands are a type of runflat system fitted to the wheel of a vehicle before the tyre itself has been fitted. They prevent loss of control of a vehicle or trailer during a tyre blow out situation.
Loss of control is caused when air pressure is lost from the tyre, the beads become detached from the rim of the wheel and the tyre edge drops down into the wheel well (see below):
Picture shows where, under zero inflation pressure, the bead of the tyre has dropped into the well of the wheel resulting in loss of control of the vehicle
The Tyron system is a steel band that is fitted to the wheel. In effect, it closes off the area in the well into which the tyre edge would otherwise drop (see below):
Picture shows a cross section of a wheel with a Tyron band fitted effectively closing off the well area of the wheel
Tyron Safety Band