Why do shopping carts do this?

Question

We've all had shopping carts that like to "walk themselves"...as in, veer to one side or the other no matter how much you try to push them straight. Why do they do this?

Answer 1

the wheels are clogged, broke

Answer 2

A properly maintained shopping cart has two wheels in the back which roll forward. The secret is the front CASTER wheels. If the pivot point in the center is free and the small axles inside the front wheels are free it'll roll any way you want it to go.

Bad shopping carts usually have binding or crooked (from wear) caster wheels which makes the cart hard to control and steer properly.

If you look at a shopping cart front set of caster wheels you will notice the center steering pivot point actually leads the axle in the center so that they always follow the cart as you push it. Crappy carts have seized center posts and or binding axles inside the wheels. That's why people have wrecks in aisles.

Google: Caster wheels on The Wikepedia Encyclopedia or anywhere on the net.

Answer 3

They get worn out and the stores never do any maintenance on them like greasing the wheel bearings and so forth.

Answer 4

Over-use often leads to the wearing of the wheels and the hinge mechanism. This general deterioration also depends on the material. Shopping carts are specifically designed to be moved in motion for sustained periods of times, you're best bet is just to get a good one!

Answer 5

they wear out just like everything else

Answer 6

They get bent from blowing around parking lots.

Answer 7

The frames get bent, the ball bearings that allow the casters to swivel get dry and don't rotate properly.