The belts in a multiple V-belt should be replaced __________.

• A. In sets
• B. Randomly during maintenance
• C. Individually
• D. As soon as one belt slips

Answer: (A)

When several belts share a drive, they must behave like a matched group. Replacing them in a set ensures all belts have similar wear, length, tension, and stiffness, so torque is distributed evenly and the drive remains balanced. If only one belt is replaced or if replacements are done randomly, the new belt will differ from the others, leading to unequal loading, faster wear on the older belts, slipping, vibration, and potential pulley damage. Waiting for a belt to slip is a reactive approach that can mask mismatches and cause more problems. Replacing all belts together restores uniform performance, which is why belts in a multiple V-belt should be replaced in sets.