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Begin OCR Text:
F ' W H E E_ A __ _ _ _ E__
WHEE_ A___E_ Ver_ical line
for the uehicle to have good steering properties
and a minimum of tyre wear. the front wheels must
have certain pre-determined settings. generally
known as the wheel angles. The wheel angles refer
to the caster. camber. hing pin incIination. toe-out
and toe-in.
CASTER
Caster generally refers to the longitudinal inclina_
tion (forwards or backwards) of the king pin. As
this vehicle does not have a king pin. the caster
consists of the angle between a uertical line and a
line through the centre of the ball joints (Fig. 6_4). . Wz_C_VozO
CAMBER Fjg. 6-_. C,_b,, ,,d _i,g pj, j,,jj,,_io,
Camber is the inclination of the whee_ itgeIf out- B=King pin inclina_ion C=Cambe,
wards or inwards. li is positive if the wheel ig jn-
cIined outwards (see C. Fig. 6-5) and negative if
the wheel inclines inwards. faulty camber causes
uneven tyfe weaf. KING PIN INCLlNATIoN
King pin inclination means the inCIination of the
king pin inwards. Since this car doeg not haue a
king pin. the inclination is represented by an ang_e
made between a vertical line and a line through the
Ver__ic8_ _ine Centre of the ball joints (B. Fig. 6-f).
King pin inclination causes the centre lineg of the
ball joints and the wheel to approach each other
towards the road surface. This makeg the whee_
easier to turn. The inclination a_go aggigtg the
tendency of the wheel to run straight forwardg
since the car is lifted very slightly when the wheels
are turned.
TOE-OUT
When driving round a bend. the wheels roll at dif-
_ ferent radii. For them to have the same pivoting
Z__OI çentre, and çongequently minimum tyre wear, the
front wheels must be turned to different e_tentg.
Fig. 64. C8__e_ ThiS relationShip iS determined by the shape of the
A=Caster Steering rod and steering armg. gee Fig. 6-6. 6.3
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