Set Back adjustment

Frontal wheel alignments are very important to obtain the best steering reactions.
Ordinally toe angle and camber ones are put an emphasis on, but caster angle values on both sides must be exactly the same as to seconds angle value. Of course they have intimate relations with SAI(Steering Axis inclination) three dimensionally that is the same meaning as Included Angle, plus camber angle value.
So the first step in wheel alignment procedures should be the establishment of frontal set back, otherwise leter adjusting tasks would be constructed on ill foundation. The difference on both side at minute angle revel would produce weak, soft ,right and unreliable steering however precisely the following adjustment were established. On the other hand, cambers and toes are established so precisely on fixed set back with no error, the steering reactions would be very tight and reliable in centric position if thrust angle error exists in condition with two centric positions including pseudo one. But relatively easy to feel and to find out the trust angle error in that circumstance, in correct set back adjustment.