tri 4 link Q

[redzook]

My statement was correct. Yours is incorrect.

I will give a procedure that anyone should be able understand and test.

Take a triangulated 4 link, with uppers converging at the axle and lowers converging at the chassis. Remove the springs, shocks and wheels, so that they do not resist axle articulation. Suspend it so the axle is high off the ground.

Mark points on the ground, directly below the axle ends of the upper and lower links.

Now push the axle so that it articulates. If the joints at the ends of the links, or the links themselves, do not bind, the axle will swing easily (except for out of balance weight of the axle). In cases where the axle was not restricted by the chassis, and the joints at the links allow, the axle could rotate nearly 90 deg.

It will be clear (even to blind freddy), that the axle rotates about a point near where the uppers converge (the roll centre). The ends of the uppers hardly move to the side. But the lowers, which attach to near the outer ends of the axle, move considerably to the side as the axle articulate.

When the uppers converge at the axle, the axle end of the lowers could not move to the side, if as you claim, the lowers resist the side load.

Sorry to hijack your thread 4sum4. redzook calls BS, but can't back it up. This thread should go back to what it was about.

hijack off.

isnt that a combination of both the lower and upper links ie Roll center height

as it would do the exact same thing in the link setup of the picture i posted
and as u said the lower links there are the ones controlling the side loads

just thought that was a flaw in your example of why the lowers arnt controlling the side load


take it to extremes

u have the picture i posted

now triangulate the uppers 2 inch each side so they are still extremely wide but they are triangulated (there you have your tri 4 link)

so the upper links are almost parallel but they do converge at the diff end slightly
while the lowers are still triangulated like the picture

that has taken it to the extreme so people can see what i am talkin about

the diff would still be located under the car easily (side to side movement)
it is a Tri 4 link when viewed from the top
and in this case the lowers(wich converge at the chassis) would be doing most of the sideload resisting

thats the only way i can explain it if you still disagree i give up

[Wendle]

you can triangulate whatever you want. as long as at least one pair of links is triangulated in comparison to the other pair it won't move sideways.

the setup redzook posted works really well in a front end as the uppers can run alongside the engine and the lowers take up the lateral load and squeeze by under the sump.