Quote:
Originally Posted by vikram_d I know it is by design and I never said it is unexpected. All I am trying to say is that the counter rebound is there even when a car is stationary and the wheel are not straight.
I dont know about other cars but at least in the swift when I turn full lock in any direction and then turn off ignition the steering tries to straighten out by a very small extent but it cant. This is the force I am talking about. Will have to try with other vehicles and check. Maybe people can try this on there cars and post those findings here. |
What you are saying is right Vikram but have you noticed that this happens in a stationary car irrespective of the engine being start or not and i guess this is because rubber being flexible, the tyres when turned are flexed negetively at the base which is in contact to the road surface with respect to the direction they originally stopped in due to which the the slight rebound but the steering mechanicals being stronger and wieight of the vehical do not allow the rubber to flex back completely to its original place.
This is evident by the circular marks left on the tyre base which was in contact with the road surface.
Try the following.
1.Overinflate the front tyres by 5-7psi and you will see the rebound is more, similarly less when the tyres are underinflated.
2.Stop the car with the tyres locked at full, but make sure the car was rolling when the steering is locked at full and the stop. Tyre pressure should be normal as usual . Now turn the steering straight, you will notice the rebound again.
This effect is not because of the counter rebound which occurs due to design and movement as others suggested rightly but due to the characteristics of rubber IMHO.
IMO if a vehicle is parked on level surface it would not matter if the wheels are turned in or straight as the weight is not biased and is being transferred to the suspensions and wheels when wheels are turned as it would if the wheels were straight.
But on inclines its different and hugely depends on which side the car is facing.
If the car is parked on a slope facing the incline side(north/up) then the weight of the vehicle is transferred to the rear wheels and suspensions, so if the steering is turned or straight it would'nt matter.
On the other hand if the car is facing the decline side(south/down) then the weight of the vehicle is transffered to the front suspension and wheels and also the steering mechanism and brakes as the dead weight wants to move forward and straight but the direction of the wheels force the weight to be transffered in the direction of the wheels, but since the vehicle is stationary and not moving, this creates an opposing force where the weight is trying to move straight and forward but is being stopped by the brakes and opposing direction of the wheels. So in this case it is better if the wheels are turned in straight and rocks or bricks placed in front of the wheels would stop the weight rolling. What this does is transfers the weight to the tyres which under stress can flex against the rocks thus reducing/minimising stress on the suspensions and steering mechanism.
PS: Sorry for the lost post but just my 2 cents. |