Roll oversteer means that the rear end will "steer" into the turn as
the body leans over. What this does is limit the speed at which the
car will corner as the back end starts to come around. This
incidentally unloads the OUTSIDE tire (the one taking most of the load
in this case) by reducing the slip angle -- and the tightness of the
turn. Since the front end sway bar is pretty heavy, this will also
lift the inside rear corner, and can even lift the inside front tire,
all with the intended consequence of making the driver slow down! The
jacking sensation at the rear is a warning you are approaching the
handling limit of the car, with plenty of time.
End result is that the W123 won't corner was well as the W115/114 at
the same speed, but you won't blow the outside tire off the rim, either
-- needless to say, THAT will reduce handling to near zero!. W115/114
chassis cars handle FLAT, very little body roll, quite nice, but I've
both been warned about the tire unmount and talked to people it
happened to -- lucky, there were no trees when he ran off the road.
Roll oversteer is very easy for the driver to feel and to compensate
for (lift the accelerator, for instance), and the car remains stable
and in control. Benz may have overdone it in the W123, but after all,
these are really luxury rides, not sports cars.
The W124 does indeed handle better (by the numbers generated), but is
somewhat less forgiving. Overdrive it hard enough and the rear end
loses traction before the front does, and it goes end for end with
nowhere near as much warning as the W123. It also is harder to get
back under control when this happens, too -- less margin for error.
Peter
