Off Panhard bar

[Greg Hermann]

>A DeDion suspension is a dead axle connecting each rear hub.  This axle is
>located by various rods as is a live axle.  The final drive is mounted to
>the frame and halfshafts connect to the hubs.  The advantage is the
>kinematics of a live axle with low unsprung weight.  Usually the half shafts
>have to change in length to accommodate suspension travel.  In the Rover,
>the dead axle is allowed to change in length while the halfshafts take the
>cornering loads.  I guess they thought one plunge joint is cheaper than two.

Well-not that the Rover had enough power to make it much of a factor, but
the slipjoint in the Di-Dion tube was never bound up by torque. And, per my
later explaination, the fixed length halfshafts saved any need for any
OTHER lateral locating links at all--so Rover saved a couple of ways. I
have often thought that a copy of this set up--done using a big-block Vette
center section--would be a VERY GOOD rear suspension for a high powered
roadster--something like a Cobra replica--cuzza no torque binding in the
rear halfshafts, and nice, predictable, live axle type handling with all
that torque, and the bonus of decent behavior in bumpy corners cuzza the
low unsprung weight!!
>
>Having an A arm locating the rear axle like the old Alfas works pretty well.
>Having it offset a little actually compensates for the torque reaction of
>the axle.

Hadn't thought of that, but of course it does. Prolly why the ball joint
was on the driver's side of the pumpkin. They also put the battery in the
right side of the trunk.
 And the stresses on the triangle are rather impressive--particularly with
a "BIT" of extra power!! It was amazing how much more planted the car felt
coming out of corners after replacing the two rubber bushes in the body end
of the triangle with bronze bushes!  It had a little side to side twitch
that disappeared completely after the bushings were in. (Nothing wimpy,
either, IIRC, the ID of the bushings was about 1-1/4", mebbe 2-1/2" long
each.) And the "extra power" was not too wimpy, either. The 1600 in that
car made about 170HP (NA, no juice), and the car would turn low 14's in the
1/4. One of the funnier things it ever did was pull about a 125 YARD hole
shot on a 400 Fireturd at a stoplight--The poor guy was tryin' to show off
for his girl friend. Don't think he got any that night!

Regards, Greg