Phenom question

My sons going to run a phenom this year. Curious also as I have it set neutral at the moment. I am guessing to reduce rear flex but to push or pull would be my ultimate question on reaction.
What the tie rod assembly for at the left rear to the tube under seat back for or reason for it
It stiffens the lr chassis tube in the lateral direction without stiffening in vertical direction .

The lr bearing is pinned to the axle. RR bearing can be held with clamps or floated to keep axle from binding chassis.
Yeah, we took ours off and the kart has been considerably better this year. Especially the way it reacts to changes made in setup.