Originally Posted by
Jimmy86
I have also read the forum post u quoted. As i understand it the 6 degree beam wont change ur rollcenter. Just get rid of some of your bumpsteer. U are probably better than me on the geometry but as I understand it this is how u measure your rollcenter on a semi-trailing rear suspension
That means u only move ur rollcenter forward since ur not changing the pivot axle angle up/down. Or am I totaly retarded?
Thats why I wanted to move mine up abit.
The picture you showed how to determine the rear roll centre is correct, but I'm not sure whether you interpreted it correctly. In the upper picture the instant centre is where the 2 dashed lines intersect. But in that picture you cannot see how high the instant centre is. In the bottom picture you see the instant centre from a front view, where the height is visible. Where the line from the tyre centre to the instant centre crosses the centre line from the car is where the roll centre is.
The roll centre is always exactly between the two wheels, it cannot move forward or backward.
On a 6 degree beam the instant centre is much further away than on a standard (18 degree beam) because the angle of the upper dashed line is much smaller.