Editing Steering (section)

===Geometry===
[[File:Ackermann turning.svg|thumb|250px|right|Ackermann steering geometry]]
The basic aim of steering is to ensure that the wheels are pointing in the desired direction to move the vehicle as required. This is typically achieved by a series of linkages, rods, pivots, and gears. One of the fundamental concepts is that of [[caster angle]]. Each wheel is steered with a pivot point ahead of the wheel, which tends to make the steering self-centered in the direction of travel.

The steering linkages connecting the steering box and the wheels usually conform to a variation of [[Ackermann steering geometry]], to account for the fact that in a turn, the inner wheel travels in a path of smaller radius than the outer wheel, so that the degree of [[toe (automotive)|toe]] suitable for driving in a straight path is not suitable for turns. The angle the wheels make in the vertical plane, known as [[camber angle]], also influences steering dynamics as do the tires.
{{clear}}
{{Gallery
|width=120 | height=120
|align=center
|File:Caster angle.svg|[[Caster angle|Caster angle θ]] indicates [[Kingpin (automotive part)|kingpin]] pivot line and gray area indicates vehicle's tire with the wheel moving from right to left. A positive caster angle aids in [[directional stability]], as the wheel tends to trail, but a large angle makes steering more difficult.
|File:Curves, described by a simple moving vehicle.ogv|Curves described by the rear wheels of a conventional automobile. While the vehicle moves with a constant speed its inner and outer rear wheels do not.
}}

Steering wheel turning is often measured in terms of number of full 360-degree turns to go '''lock-to-lock'''<!-- bolded per [[WP:MOSBOLD]] as a redirect link -->. This is when the steering input mechanism is restrained at its mechanical limit from the full right-turn stop to the left-turn stop.