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The bead seat diameter of a tire refers to the measurement of the tire’s diameter at the point where the bead heel seats on the rim. This dimension is crucial because it determines the size compatibility between the tire and the wheel rim.

On the sidewall of a tire, you can find markings that indicate its dimensions. Typically, the bead seat diameter is not directly marked on the sidewall. Instead, you’ll find markings such as the tire size (e.g., 225/45R17), where the last number (17 in this example) indicates the diameter of the rim in inches. This rim diameter corresponds to the bead seat diameter, which is the critical measurement for ensuring that the tire fits properly onto the wheel rim.

Correct matching of the bead seat diameter between the tire and rim is essential for safe and efficient operation of the vehicle, ensuring proper tire mounting, sealing, and performance.

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