Carrol Smith covers Watts linkages in his book "Engineer to Win". (A
great book) The Watts linkage will allow close to purely vertical motion
and eliminate the side to side motion, this is over a short range and
the bars have to be set up correctly. An additional advantage is that
you can control where the roll center is for the rear suspension. With
just a rear axle the roll center is the center of the pumpkin. With a
Panard bar the roll center moves from side to side depending on the
direction of the turn, and is located at the pivot of the rod. (Right
pivot for left turn and left pivot for right turn, I think) For the
Watts linkage to work at its best they are normally set up with the
outboard ends of the rods attached to the axle and the bell crank
attached to the frame, which means some structure needs to be built that
will support the bell crank. The roll center becomes the center pivot of
the bell crank. That is how you can change the roll center, by moving
the bell crank up and down.
I use this system on my GT350 race car. I'm not sure if it is really
worth the extra effort over a panard rod.
Craig Wright
Rich Atherton wrote:
>
> Hey everyone. I was just cruising through some pages about my favorite
> Rover 215 engine, and ran across this picture of a WATTS linkage Panhard rod
> setup that looked like something I had drawn up a year or so ago, and sent to
> One of the Laifmans....(I can not get them straight).. Anyway, I know the
> Alpine's can use one, and the Tiger's always seem to either tear loose from
> the frame, or do enough damage after 30+ years that repairs need to be done.
> The drawing I did was a cantilever system for centrally locating the rear end,
> without out it being pushed or pulled out of the centerline because of the arc
> of the travel of the Rod . this system keeps it right where it is. This pic
> is from the underside of the car while in a rotisserie. The Car is a Triumph
> TR7 / TR8 it wasn't clear which it was. They also were adding Porsche Brakes
> and other stuff, but the WATTS linkage was well done. Here's the picture...
>
> http://users.online.be/~gd31496/images/9.jpg
>
> I'm sure some of you more metallic types out there could do this for your
> Tiger. Probably could build a Kit for everyone to use... the mind Boggles..
> :-)
>
> Rich
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