How does a car steering wheel automatically return to its center when accelerating after a turn?
In: Engineering
Because of something called ‘castor angle’
Notice how in [this](https://thumbs.dreamstime.com/z/brakes-car-removed-wheel-109315615.jpg) picture the whole shock assembly is slightly tilted backwards?
If you imagine following the line that makes until it touches the ground, it’s going to be slightly *ahead* of the point where the tire itself (when it’s fitted) touches the ground.
What that means is the contact point of the car’s steering wheels is behind the point around which they rotate (when steering).
In other words, they’re arranged exactly the same way as the wheels on a shopping cart. The point they touch the ground is [behind the point around which they rotate](https://bigbasketco.com/wp-content/uploads/steel-wire-cart-25w-05.jpg).
What this does is literally drag the wheels into line with the movement of the car once you’re moving forward.
As another response has said, if you reverse, the wheel will want to spin around, not for the reason they’ve stated, exactly, but for exactly the same reason pulling a shopping backwards causes the wheels to spin round the other way.
Latest Answers