double wishbone suspension
the basic design double wishbone suspension is an independent suspension system
it allows each wheel to act independently from the others this is accomplished by two wishbone-shaped
arms also called double-a arms that are located between the steering knuckle and the chassis
the upper and lower control arms have ball joints at both ends to enable movement in all directions
each wishbone or arm has two attachment points on the chassis and one joint at the steering
knuckle vertical motion is controlled by the coil spring and shock absorber mounted on the wishbones
the spring and damper could be attached to the upper control arms and to the chassis a more
popular configuration is attached to the lower of the two a-arms as the system is much more
compact the advantage the double wishbone suspension provides the driver with a
smooth driving experience especially on bumpy roads as a more complex design
the double wishbone allows for better control over camber and body roll what is camber camber is a
measure of the tire's centerline relative to the road surface it is measured in degrees and has a
great influence on the driving dynamics of the car negative camber the top of the tire tucks inwards
positive camber the base of the tire tucks inwards
effective camber control improves handling by keeping better contact of the tire with road
while the car rolls it ensures that the tire's contact surface is evenly loaded
traditional double wishbone suspension is made up of two parallel control arms of equal length
the advantage of this is that as the tire has a positive or negative vertical motion
the tire travels in a straight line and the camber angle stays the same
in principle the double wishbone suspension always keeps the tire perpendicular to the road surface
regardless of the wheel movement this helps to ensure good handling
the disadvantage is when the car goes around a corner that camber angle changes as the car
body rolls let's look at the camber when the car goes around the corner in this case the
car is going around the right corner and the car body is going to roll to the left
for a double wishbone suspension with equal length control arms the car will have slight positive
camber on the outside tire and negative camber on the inner tire this is not a desirable design
as the outer tire is taking most of the load while the inner tire is taking less load
to solve this problem the double wishbone suspension uses a shorter upper control arm
that the tire will have induced negative camber during a vertical travel
this is beneficial when the car goes around the corner due to the shorter upper control arms
the car will have slight negative camber on the outside so the outer tire goes flat with
the road surface this is where the car wants to maintain the maximum amount of contact
the inner tire will have a slight positive camber it is pressing flat against the road
the more a double wishbone suspension is compressed the more negative camber is gained
due to the use of unequal length control arms as the car is cornering and starts to roll a
double wishbone suspension system ensures better contact of the tires with the road
the disadvantage a double wishbone suspension has more components and therefore it is more
expensive to design manufacture and maintain than other suspensions such as the macpherson
strut suspension in addition due to the large number of parts a double wishbone
suspension system is heavier and requires more space than other suspension systems
the double wishbone suspension can be used on the front and rear wheels
it is independent and above all it has almost perfect camber control
nowadays the double wishbone suspension has been the first choice for many racing and sports cars
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