It’s an almost-inevitable part of any shopping trip. You enter a store to grab a few necessities and find yourself pushing, pulling, and dragging your cart up the baking aisle as the one wheel with a mind of its own squeaks and stalls against the linoleum.
A long-circulating urban myth holds that retailers deliberately make the carts unwieldy to slow your roll down the aisle, hoping to divert your attention to more merchandise. But the national frustration is not the work of a business psychology mastermind.
The notoriously combative wheels are actually created by the repeated battering that shopping carts are often subject to. Grocery store carts are more likely to have carts with wonky wheels than other types of retailers. That’s because they are exposed to the elements much more often, and that environmental damage affects the wheels. The primary culprit, however, is often not the wheel itself, but the way it’s attached to the cart.
Over time, pulling carts through bumpy parking lots, wrestling them across the threshold of doorways, and forcing them up and down the curb warps the caster plate, the metal piece that attaches the wheel mechanism to the cart’s body. ‘If that caster plate gets twisted just a little, it might lift the wheel up, and then both wheels are not touching the ground at the same time,’ says a sales director for a shopping cart supplier company.
In a perfect world where carts were handled gently and utilized only indoors, the standard five-inch polyurethane shopping cart wheel could last between six and eight years. But replacing the wheel without paying attention to the plate and the nuts and bolts that keep everything together means that a new wheel can be just as wobbly as an older one.
Carts that are abandoned outside after shoppers load their food into their vehicles are at the mercy of extreme heat, snow, ice, and road salt. That prolonged exposure can damage the cart and its wheels.
To combat this, grocery retailers in Europe have coin locks on their carts. Customers insert a coin to ‘check out’ a cart, which they get back when they return the cart to its original place at the end of their shopping trip.
One way to enhance durability is by changing the material of the wheels from the typical polyurethane to pricier rubber. Rubber wheels have been a mainstay of motorized shopping carts for decades, providing a smooth and steady ride. Several major chains like Walmart and Target have begun using rubber wheels in their carts.
While the rubber wheels cost twice the price of the standard polyurethane ones, they can last for about a decade. However, many retailers choose cheaper parts because the upfront price is typically higher for more durable material. These companies end up needing to replace these parts more often as they get twisted and deformed.
