duckhead

A duckhead is a curved metal claw that forms part of a tyre changer, specifically the component that clamps onto the wheel rim to hold it steady during tyre removal and fitting. The name comes from its shape, which resembles a duck's head in profile, with a downward-pointing beak. It is mounted on the rotating turntable of the machine and engages with the rim flange to prevent the wheel from slipping during the demounting and mounting process.

Most tyre changers use a pair of duckheads positioned opposite each other on the turntable. They are adjustable vertically and sometimes laterally to accommodate different rim diameters and flange profiles, typically ranging from 10 to 24 inches. The clamping force is usually applied hydraulically or pneumatically. The contact surface of the duckhead is often faced with rubber or urethane to avoid marring the painted or polished rim finish.

Correct positioning of the duckheads is critical. If they are set too tight, they can crack or dent the rim; if too loose, they will not hold the wheel securely and the tyre will slip during demounting, causing the bead breaker or shoulder of the machine to fail to seat properly. The duckhead must also grip below the flange, not on top of it, so that when the tyre is being separated from the rim the leverage is correct and the rim edge does not rise up and slip free.

Wear on the duckhead clamping surface or rubber facing is common with heavy use. A worn or flattened facing reduces grip and must be replaced or rebuilt, otherwise operator productivity falls and rim damage becomes more likely. Some duckheads are designed with replaceable rubber inserts that can be renewed without replacing the entire casting.

The duckhead assembly is one of the most stressed parts of a tyre changer because it absorbs the reaction forces from the bead breaker and the tyre lever during separation. Cracks in the casting or bent stems that prevent full closure are signs of fatigue and should be addressed promptly. Proper maintenance, including regular cleaning and occasional lubrication of pivot pins, extends service life and keeps the machine safe and productive.