REVERSIBLE & IRREVERSIBLE STEERING
Reversible steering: When the deflection of road wheels is transmitted through the steering wheel to road surface, the system is called Reversible. If every imperfection of road surface causes the steering to rotate, it causes much strain on the part of the driver to control the vehicle. Therefore such of the reversibility is not desired. But, some degree of reversibility desired, so that the wheel becomes straight after taking a curve.
Irreversible steering: If the front road wheels do not transfer any deflection to the steering which is called irreversible steering. After negotiating a curve and the steering wheel not returned easily, there causes the production of undue stresses on the steering mechanism, therefore some degree of irreversible also desired.
UNDER STEERING & OVER STEERING:
Automotive engineers define understeer and oversteer based on changes in steering angle associated with changes in lateral acceleration over a sequence of steady-state circular turning tests.
Understeer and oversteer are vehicle dynamics terms used to describe the sensitivity of a vehicle to steering. Oversteer is what occurs when a car turns (steers) by more than the amount commanded by the driver. Conversely, understeer is what occurs when a car steers less than the amount commanded by the driver.
Under steer: When the front slip angle is greater than that of rear, the vehicle tends to steer in the direction of side force. Then it is known as under steer. This provides greater driving stability, especially when there is a side wind. Front wheels lose their traction and cause the car to go wide. It can be corrected by stiffening the vehicle’s rear chassis.
Over Steer: When the rear slip angle is greater than that of front slip angle, the vehicle tends to move away from the direction of center path. This is known as over steer. This is advantageous when the vehicle moving on the road having many bends curves. Rear tyres lose grip and causing the rear end of the vehicle slides out. It can be corrected by stiffening the vehicle’s front chassis.
Counter-steering is used by single-track vehicle
operators, such as cyclists and motorcyclists, to initiate a turn toward a
given direction by momentarily steering counter to the desired direction
("steer left to turn right"). To negotiate a turn successfully, the
combined center of mass of the rider and the single-track vehicle must first be
leaned in the direction of the turn, and steering briefly in the opposite
direction causes that lean.
Opposite lock, also commonly known as counter-steering, it is a colloquial term used to mean the steering associated with the deliberate use of oversteers to turn a vehicle rapidly without losing momentum. The terms "opposite lock" and "counter-steering" refer to the position of the steering wheel during the maneuver, which is turned in the opposite direction to that of the bend. Opposite lock can be a useful technique for saving a car from a loss of control such as an unintentional skid.
Drifting is a driving technique where the driver intentionally oversteers, with loss of traction, while maintaining control and driving the car through the entirety of a corner. The technique causes the rear slip angle to exceed the front slip angle to such an extent that often the front wheels are pointing in the opposite direction to the turn (e.g. car is turning left, wheels are pointed right or vice versa, also known as opposite lock or counter-steering). Drifting is traditionally done by clutch kicking, then intentionally oversteering and countersteering. It is the spectacle of smoking tyres. The bias-ply racing tyres with a high slip angle are more useful to this driving style. Japan is the birthplace of drifting. It was most popular in the races and almost exclusively in rear-wheel-drive cars. Its judging style for competition is based on line, angle, and speed.
Crooked Steering Wheel:
Crooked
wheel steering is undesirable for steering system and which indicate that the
vehicle is not in proper alignment or vehicle must require to wheel alignment.
Crooked wheel condition can observe during running a vehicle and seen from
front, now a complete vehicle is deflected from its longitudinal axis.
Reversible steering: When the deflection of road wheels is transmitted through the steering wheel to road surface, the system is called Reversible. If every imperfection of road surface causes the steering to rotate, it causes much strain on the part of the driver to control the vehicle. Therefore such of the reversibility is not desired. But, some degree of reversibility desired, so that the wheel becomes straight after taking a curve.
Irreversible steering: If the front road wheels do not transfer any deflection to the steering which is called irreversible steering. After negotiating a curve and the steering wheel not returned easily, there causes the production of undue stresses on the steering mechanism, therefore some degree of irreversible also desired.
UNDER STEERING & OVER STEERING:
Automotive engineers define understeer and oversteer based on changes in steering angle associated with changes in lateral acceleration over a sequence of steady-state circular turning tests.
Understeer and oversteer are vehicle dynamics terms used to describe the sensitivity of a vehicle to steering. Oversteer is what occurs when a car turns (steers) by more than the amount commanded by the driver. Conversely, understeer is what occurs when a car steers less than the amount commanded by the driver.
Under steer: When the front slip angle is greater than that of rear, the vehicle tends to steer in the direction of side force. Then it is known as under steer. This provides greater driving stability, especially when there is a side wind. Front wheels lose their traction and cause the car to go wide. It can be corrected by stiffening the vehicle’s rear chassis.
 |
| Fig 1: Under Vs Over Steer |
 |
| Fig 2: Dynamics of Over & Under Steer |
Over Steer: When the rear slip angle is greater than that of front slip angle, the vehicle tends to move away from the direction of center path. This is known as over steer. This is advantageous when the vehicle moving on the road having many bends curves. Rear tyres lose grip and causing the rear end of the vehicle slides out. It can be corrected by stiffening the vehicle’s front chassis.
 |
| Fig 3: Counter Steering |
Opposite lock, also commonly known as counter-steering, it is a colloquial term used to mean the steering associated with the deliberate use of oversteers to turn a vehicle rapidly without losing momentum. The terms "opposite lock" and "counter-steering" refer to the position of the steering wheel during the maneuver, which is turned in the opposite direction to that of the bend. Opposite lock can be a useful technique for saving a car from a loss of control such as an unintentional skid.
Drifting is a driving technique where the driver intentionally oversteers, with loss of traction, while maintaining control and driving the car through the entirety of a corner. The technique causes the rear slip angle to exceed the front slip angle to such an extent that often the front wheels are pointing in the opposite direction to the turn (e.g. car is turning left, wheels are pointed right or vice versa, also known as opposite lock or counter-steering). Drifting is traditionally done by clutch kicking, then intentionally oversteering and countersteering. It is the spectacle of smoking tyres. The bias-ply racing tyres with a high slip angle are more useful to this driving style. Japan is the birthplace of drifting. It was most popular in the races and almost exclusively in rear-wheel-drive cars. Its judging style for competition is based on line, angle, and speed.
 |
| Fig 4: Drifting |
This is
the condition for disturbance in wheel alignment or steering geometry of the
vehicle. Crooked wheel means a deflection of complete chassis frame, from its
vehicle longitudinal forward vertical axis line. As shown in below Fig 5.
 |
| Fig 5: Crooked Steering Wheel |
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