Which condition causes a centrifugal clutch to engage?

• A. Low speed
• B. High torque
• C. High rotational speed
• D. Low load

Answer: (C)

Engagement is triggered by high rotational speed. In a centrifugal clutch, spinning weights are mounted on arms that are held inward by springs. As speed increases, centrifugal force on those weights pushes them outward, compressing the springs and pressing the clutch shoes against the drum. When the speed reaches the clutch’s engagement threshold, enough contact is made to transfer torque. At low speed the centrifugal force is too small, so the springs keep the shoes retracted and no drive is transferred. Torque level or load affect how much torque is transmitted once engaged, but they don’t cause engagement—the trigger is reaching the required speed.