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Re: rear suspension geometry

To: "teds" <>, "MGList (E-mail)" <>
Subject: Re: rear suspension geometry
From: "Harlan Jillson" <>
Date: Sat, 7 Aug 1999 18:12:47 -0500
   In a word, yes.  Angling the shock forward does reduce its efficiency.
The resistance of the dampner ( shock), which is used to dampen the
oscillation of the springs during compression and rebound, is reduced by a
factor related to the cosine of the angle from 90 degrees.
  In the case of these shock conversions on B's,  most of the shocks used
have far too much dampening for the spring rate and weight of the B, so the
reduction is probably an advantage,  the racers on the list could tell you a
lot more.
   A lot of the stiffness in the suspension of the B is in the spring rate.
The front springs are running something like 480 pounds per inch of
compression, and the rears are somewhere around 120 to 130 pounds per inch
 this from books, not experience....).  The rear leaf springs also serve as
traction bars ( sort of ) to distribute the load to the body/frame.  The
shocks/dampners are there to 'dampen' out the spring oscillation.  The
stiffness of the shock relates to how fast this happens.  Another thing to
remember is that most shocks resist compression and extension at different
rates.   So a real stiff shock will feel make the suspension feel hard, but
depending on the resistance to extension the rebound rate may not be bad.
All of this relates to two things,  how it rides, and how well the tire
maintain contact with the road.  Too little dampening and the car will
bounce until the oscillation settles out, to much and it will ride like a
gravel truck, and won't keep the tires in contact with the road.
   If you read some of the reports some folks have made on these shock
conversions, you will find they run the full gambit, most of the adjustable
racing shocks ( spax, konis, etc) are way too stiff except and their lowest
settings, and the non-adjustables may be fine, depending on which shock is
   All of this is what I've gleened from reading the material some of the
more informed folks have put up on the web, and my own limited experiance.
I'm currently doing a shock conversion, so if you like I'll let you know how
it turns out.

-----Original Message-----
From: teds <>
To: MGList (E-mail) <>
Date: Friday, August 06, 1999 11:14 PM
Subject: rear suspension geometry

>a question on the rear shock replacement with tube shocks...
>my 77 mgb came with this done, I have some kind of Monroe shocks in the
>however my car has a real stiff rear suspension, in looking at the
>of travel of the shock, I'm wondering how this works as the shock itself is
>not sitting straight up and down but it is tilted forward, doesn't this
>the dampening action less efficient ?
>thanks, Ted

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