Front/Rear Wheels Turning: Pros & Cons

[forum1]

why don't car wheels turn from the rear as opposed from the front?

surely this is the same as traditional cars nowadays but with a different sensation in turning right?

what I would like to know is what are the pros and cons in each circumstance?

Also as a plus I know there are cars with 4 wheel steering where all 4 wheels are used to turn but why don't the rear wheels turn to the degree as much as the front ones?

thanks for any possible answers forwarded

 

[rcgldr]

Normally rear wheel drive systems are difficult to control. The Thrust SSC, a super sonic land vehicle, used rear wheel steering.

http://en.wikipedia.org/wiki/ThrustSSC

http://www.roadsters.com/750

prototype:

 

[Meir Achuz]

With rear turning, a turn to the left would swlng your back to the right.
Don't try that on the highway.

 

[forum1]

you wouldn't severely turn that hard on a highway unless you were suicidal just like a normal car right? but agreed a con would be that you would have to sense the rear end more precisely being mindful of your surroundings

however surely if you had either a rear or mid engined vehicle with the rear wheels used for turning would there not be an advantage?
such as...
more weight on rear tyres to provide better grip.
car slide where rear wheels loose traction therefore with rear wheel steering would you not less likely slide??
going to the extreme you could have 1 wheel at the front with 2 rear steered wheels therefore reducing weight.
a rear spoiler would also emphasise an element of control under speed.


am I just babbling "used food" or is this making sense??

 

[Phrak]

At low speeds you gain manuverability.

At high speeds you're asking for trouble. The further back the center of gravity, the worse it gets. To turn right, you are first redirecting the inertia to the left. This could induce a driver assisted roll-yaw couple that could end up rolling the car. It would be a really bad idea in a midengine design.

Automobiles that have been designed with four wheel steering have the rear wheels turning opposite what you might expected for highway speeds. That is, at high speeds, as the front wheels turn clockwise, so do the rear wheels, but to lesser degree. At low speeds, they will turn in opposite directions for tighter turns.

 

[Cantab Morgan]

This has been tried, after a fashion. Google the Dymaxion car, which was created by none other than Buckminster Fuller. This was a three wheeled vehicle, with steering on the lone wheel in the back. Support for the design waned when one was involved in a terrible crash.

 

[forum1]

cheers guys I feel very enlightened on this topic that grabbed my interest!