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RE: Adjustable Swaybars - One or Both Ends?

To: "Team. Net (E-mail)" <autox@autox.team.net>
Subject: RE: Adjustable Swaybars - One or Both Ends?
From: "Meyer, Brian J" <Brian.Meyer@Wichita.BOEING.com>
Date: Tue, 3 Aug 1999 15:01:30 -0500
He's right. Adjustment only needs to be made on one end. However, adjusting
only one side is only half as effective as doing both. For example, lets say
a swaybar has adjustment range so that the effective length of the arm
ranges from 4 inches to 6 inches. If the bar is set on full soft on both
sides, both arms will be 6" long. Adjusting one side to 4" will only take it
to "medium", and adjusting both sides to 4" will be full stiff. This is
assuming the theoretical ideal bar, with frictionless bearings for mounts,
and so on.

Something else I must comment on... a sway bar does not transfer load from
one side to the other. It only resists helps the body resist roll by adding
roll stiffness. Weight transfer is only affected by the height of the CG and
the width of the track.

The difference in the total roll stiffness from the front suspension to the
rear suspension WILL affect weight transfer from the front to rear during
steady state cornering, which is why changing the roll stiffness (by
adjusting the bar) will affect the balance of the car.

-Brian Meyer
Wichita Region SCCA


> ----------
> From:         John Coffey[SMTP:johncof@ibm.net]
> Sent:         Tuesday, August 03, 1999 2:43 PM
> To:   Team. Net (E-mail)
> Subject:      Adjustable Swaybars - One or Both Ends?
> 
> In a discussion with a local suspension guru the point was made that
> adjustable swaybars really only need to be adjusted on one end, thus the
> adjustable bars that have adjusting holes on both ends really only need
> the holes on one end.  The basis for this argument is that a sway bar is
> just a spring with a constant rate so a 100 lbs pushing up on one end will
> push down with 100 lbs on the other (assuming no preload on the bar).
> 
> Thinking about this in the context of vehicle roll (which the sway bar
> exists to control) it appears true.  A sway bar transfers load from one
> side of the vehicle to the other at a constant spring rate and the lever
> length of the sway bar ends would not affect the amount of load
> transferred (again, we're talking about vehicle roll).  I don't think its
> true in single wheel bump but that's another issue.
> 
> This was a new idea to me but it makes sense (after thinking about it and
> drawing a lot of pictures).  What do you folks think?
> 
> ----------
> John Coffey
> johncof@ibm.net
> 

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