This document discusses wheel geometry and the steering system requirements. It describes camber as the tilt of the car wheel from vertical, with most manufacturers specifying a small positive camber of 2-3 degrees for front wheels and negative camber for rear wheels to increase cornering ability. Caster is defined as the angle between the kingpin centerline and vertical plane of the wheel, typically about 3 degrees, which helps steering effort and recovery. Toe-in and toe-out refer to the front wheels being set closer together or farther apart at the front than the rear while stationary.

1. WHEEL GEOMENTRY
KRISHNAMOORTHY R
15M907

2. Introduction
The steering system allow the driver to control the direction of
vehicle travel.
The following are the secondary function of steering system:
• (1) It provides directional stability of vehicle when going straight
• ahead.
• (2) It provides straight ahead recovery after completing a turn.
• (3) It helps in controlling wear and tear of tyres.
• (4) It converts the rotary movement of the steering wheel into an
• angular turn of the front wheels.

3. The following are the requirements of a good steering
system.
(1) The steering mechanism should be very accurate and easy to
handle.
(2) The vehicle should be steered with a minimum of effort so that the
driver does not feel driving fatigue.
(3) The steering mechanism should be affected by the side thrusts,
cornering forces and wind effects.
(4)The mechanism should have a tendency to regain the straight ahead
configuration after steering need is over.

4. Camber
• Camber is the tilt of the car wheel from the vertical.
• The tyre life will be maximum when camber angle is zero.
• Caster is also know as wheel rake.
Effect:
• Excessive camber causes
• improper contact of the wheel.
Amount:
• Most manufactures specify
• A very small camber. Usually 2º to 3º from Straight up and down.

5.  Positive Camber Angle
• If tiles outward it is positive camber angle.
• Positive camber angle Primarily used on
front wheels.
 Negative Camber Angle
• If tiled inward it is negative camber angle.
• Negative camber angle Primarily
• used on rear wheels.
 Reasons to use Negative Camber
• Increased cornering ability.
• Increases road shock & component wear

6. The angle between the king pin Centre line
and the vertical, in the plane of the wheel is
called caster angle.
Effect: Incorrect caster can produce
Difficulties like hard steering, Pulling to
one side when brakes are Applied.
Amount: It will be about 3º
Caster

7. Toe-in
• Toe-in is the amount by which the front wheels are set closer
together at the front than at the rear.
• when the vehicle is stationary.
Front = 79 in.
Rear = 80 in.
Total toe-in = 1 in

8. Toe-Out
The wheel may be set closer at the rear than at the front in
which case the difference of the distance between the front wheels at
the front and at the rear is called toe-out.
• Front = 80 in.
• Rear = 79 in.
• Total toe-out = 1 in