Technical Dictionary

Balance/Imbalance

The state in which a tyre and wheel spin with all their weight distributed equally. To correct an imbalance, a trained mechanic will add weights on the interior or exterior of the wheel.

Bead

The section of the tyre that sits on the wheel. Inside, there is a round hoop of steel wires, wrapped or reinforced by body ply cords, that clamps the tyre firmly against the wheel rim.

Bead Filler

Responsible for transferring propulsion and braking torque from the wheel rim to the road surface contact area.

Bead Chafer

A key component of the tyre that is the contact point between the tyre and the wheel, designed to withstand forces the wheel puts on the tyre during mounting as well as the dynamic forces of driving and braking.

Banded At Zero Technology™

Michelin® BAZ Technology™ uses spiral-wrapped nylon strips applied in the tread area atop the steel belts at zero degrees. BAZ Technology™ opposes centripetal forces that can cause tyre distortion at high speeds1. BAZ Technology™ optimizes high-speed handling and durability.

Bead Tension Structure

Two sidewall plies wrapped around each bead wire in opposite directions providing lateral stability but flex to absorb road irregularities.

Belt

A rubber-coated layer of cords that is located between the body plies and the tread. Cords are most commonly made from steel but may also be made from fiberglass, rayon, nylon, polyester or other fabrics.

Bias-Ply

A type of tyre with crossed layers of ply cord running diagonally to the center line of the tread.

Bolt Circle

The diameter of an imaginary circle drawn through the center of each lug nut hole and then measured from two holes that are directly across from each other. The measurement is used in selecting the proper wheel for replacement.

Braking Torque

A technique practiced by drag racers and road testers to improve their off-the-line acceleration; applying the brake and throttle at the same time, increasing the engine rpm until release of the brake.

Breakaway

A term used to describe a loss of traction when negotiating a curve or when accelerating from a standing start. The tyres slide against, instead of grip, the road surface.