Which component is the wearing surface on the outer circumference of the tire?

• A. Carcass
• B. Tread
• C. Bead
• D. Sidewall

Answer: (B)

The wearing surface on the tire’s outer circumference is the tread. The tread is the patterned rubber layer that actually makes contact with the road, providing traction, wear resistance, and the ability to channel water or debris away from the contact patch. As the tire rolls, the tread wears down, so monitoring tread depth is essential for safety. The remaining parts serve different roles: the carcass is the internal fabric structure that provides strength and shape; the bead anchors the tire to the wheel rim; and the sidewall is the rubber area between the tread and bead that handles flex and side loads but is not the primary wear surface.