Move upper arm mount rearward to allow caster adjustment

going back to caster change, when i measured bump steer on my '66 to see what the suspension does as it moves i found it changed Caster by 9 degrees from full droop to full bump and about 4 degrees over about 2 inches of suspension movement around ride height. (this was on old rubber bushes)

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and this is what i found on bump steer


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i think bump steer is actually built in to cause the steering to understeer as the car leans into a corner making it safer for the ordinary driver.


just dropping the K frame by 1/4 inch reduced bump steer in a straight line but i also tested it on a slight lock and bump steer is back.


UK roads are just awful for pot holes so for me dialing out bump steer and gaining more caster at a normal ride height is the goal.
Seems like you've induced an 'S' curve that looks more normal with 1/4" k-frame drop,. Explain 'slight lock'. And also, bump steer in chassis roll is affected then?
Setting that curve usually the best you can get.
Its all just compromising to get smallest amount of bump possible with a reasonable curve, right?