THE ANATOMY OF THE TYRE
To the casual observer all tyres look alike. Don't be fooled. Today's tyres offer a degree of handling, ride comfort, traction, tread wear and fuel economy that far exceeds tyres manufactured just a few years ago.
Here are the components of a modern tyre:
The tread is the part of the tyre that comes in contact with the road surface.
The tread is made of thick rubber or rubber/composite compound with a pattern of grooves, lugs, voids and sipes. Every tyre comes with a different tread pattern, unique to that tyre.
These are needed to channel water away to help prevent aquaplaning.
Lugs are the portion of the tread that make contact with the road.
Voids are spaces between lugs that allow the lugs to flex and flush out water.
Sipes are valleys across the whole tyre. They run perpendicular to the grooves and allow water from the grooves to escape to help prevent aquaplaning.
Also known as wear indicators; these raised features at the bottom of tread grooves indicate that a tyre has reached its wear limit.
When the tread lugs are worn away enough that the wear bars connect it's time to replace the tyre.
The bead connects the rim of the wheel to the tyre. It's normally strengthened with steel wire.
It's fitted very tightly so the tyre doesn't shift.
The sidewall is the part of the tyre between the bead and the tread. It is composed of rubber for the most part and strengthened with fabric or steel cords.
The shoulder is the edge of the tread as it begins to transition into the sidewall.
Plies are cords wrapped in rubber. These prevent the rubber from stretching. The way that plies are laid out in the tyre makes a big difference to its performance.