Like a car in reverse or a forklift. What makes it feel so unstable?
In: 4
It isn’t. You’re just not used to it and haven’t practiced driving that way, so it feels foreign to you. If you backed up a car every day, or drove a rear-steer forklift every day, it would feel just as natural.
Short answer: perception.
It steers differently, but it isn’t inherently harder. It’s just not what you’re used to, so it takes a while to get your bearings
The physics are different. The weight distribution is different. You need practice to get used to it.
It’s the same concept with driving as it is with your vision, or for example inverting the controls on your video game controller.
Https://www.theguardian.com/education/2012/nov/12/improbable-research-seeing-upside-down
Can agree with others. It isn’t harder and in certain circumstances offers much more control. It’s all about geometry. Steering from the front produces a wide arc that’s much safer at high speeds. But this wide arc is super limiting at slow speeds in tight spaces. A much smaller radius is needed when picking loads from a narrow alley in a warehouse. Same with parking boats, it’s much easier when steering from the rear (although larger vessels will steer from the fore and aft using bowthrusters).
Basically, it’s:
Forward Steering = Good at Speed
Rear Steering = Good for Control at Low Speed.
It is absolutely more difficult to control, and anyone who tells you differently doesn’t understand the physics involved. Just because Joe from the warehouse can drive the forklift like an F1 car, doesn’t mean it’s a racecar.
When you remove the steering input from a front-wheel steer vehicle, physics wants to turn the front wheels back straight and you end up driving straight again.
when you remove the steering inout from a Rear-wheel steer, there is no force acting on the wheels to straighten them back out, so you keep turning unless you correct it yourself.
Grab a pencil by the tip and let it hang under your fingers. This is a *stable equilibrium*. If the pencil starts wobbling to the left, your fingers pull it back towards the centre with no extra effort from you. This is analogous to steering from the front.
Grab a pencil by the tip and flip it so that you’re balancing it above your hand. It’s harder. This is an *unstable equilibrium* because any change to the left or right will try to pull the pencil *more* to the left or right, and it takes active adjustments from you to keep it balanced like that. This is analogous to having steering at the back.
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Just like how you can *learn* to balance the pencil upwards, people can *learn* to keep cars aligned with steering at the back. Some people who are really used to it might even claim that balance the pencil upright is as easy as dangling it, like with cars. It’s fundamentally not true though.
This is also why it gets exponentially harder to drive backwards with trailers added to the back of your car, but it’s still fine to drive forwards.
It’s essentially like replacing that pencil with a chain, and trying to keep the chain straight. Dangling down, it’s pretty easy (because it’s a stable equilibrium), but it’s nearly impossible to keep a chain stacked straight upwards.
It’s not the rear steering making it unstable – it’s where the centre of mass is relative to the “centre of grip”.
The centre of grip is a point in a vehicle where if you pushed the vehicle sideways it would slide perfectly sideways without rotating.
In a car the centre of mass is in front of the centre of grip. This means when you turn hard, the car understeers (turns less than intended). This is easy to control – you just turn the steering wheel a bit more. In reverse, the car overseers, turning more than the steering input – it’s much easier to lose control in this arrangement!
Edit: Thrust ssc – the 760+ MPH land speed record vehicle famously had rear steering. It was fine since it was designed from the ground up to be stable as a rear steered vehicle.
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