Most U.S. shopping carts are equipped with front caster wheels, not unlike those on a desk chair, which can swivel in any direction. Sometimes all four of the wheels are swiveling casters, which makes the cart almost too maneuverable and hard to push around corners. More often, a cart’s back wheels are fixed to roll straight. But because carts see such high traffic, are pushed over hazardous floors, and are frequently the victims of aisle rage, it’s easy for the metal base of the cart to get bent. When that happens to a fixed-rear-wheel vehicle, the driver’s own force has to make up for the cart’s wayward path (which in turn creates more aisle rage, and so on). Proper weight distribution will help you steer: Load the heaviest items in the back, above the rear-wheel axis.
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