Imagine the hypothetical extreme situation where the steering pivot is angled so far back at the top that it’s at 45°. Now steer right, by pulling the right hand end of the axle towards you and left hand end away. The right hand end will push into the ground lifting that side, and the left will drop as the wheel is pushed away from the ground.
It’s a different mechanism for normal steering.
Absolutely agree Stefan, the effect is a lot smaller in a normal steering set up but still present. Below are the measurements I took of this effect on the three wheeler. I am using a 500mm plumbob and the variation is lock to lock with an average full lock steering angle of 27
0. Calculated out, full lock throws me 0.75
0 out of plumb to the outside of a turn with a caster angle of 4
0 - I hope that this is insignificant with all the other dynamics of the chassis/ front suspension but I intend to proceed with caution. I suspect this will show up less on a four wheel car as the outside rear will resist the twist.
Tinworm's centre pivot steering would exaggerate this effect.