I don't know of any Vanagon shocks that are variable rate using a control rod. Some Monroe sensormatics (or whatever), use slots in the cylinder. Some variable rate shocks use speed to effect damping rate. Basically a relief valve on the piston so impacts will cause the shock to reduce damping on the compression and then control the rebound thus reducing the impact shock to the vehicle.

Dennis

----- Original Message -----
From: Loren Busch <starwagen@GMAIL.COM>
Date: Wednesday, March 29, 2006 2:12 am
Subject: Very Technical Question on Shocks

> Given these conditions:
> Modern shock absorbers have variable damping rates depending on
> where they
> are in their travel.
> The variable rate is controlled by an internal metering rod that
> passingthrough an orifice and the diameter of the rod is different
> along it's
> length, allowing more or less fluid to flow depending on where the
> shock is
> in its travel.
> On a Vanagon there are at least three different lengths of stock
> springsavailable and additional after market springs of different
> length.The length of the springs will determine where the shocks
> are in their
> travel when at rest and how far (to what position) they will
> travel when in
> use while driving.
> Assuming that all the above is correct, I would expect that the
> effectiveness and performance of the shocks would be at least
> partiallydependent on what set of springs they were being used
> with.  If the spring
> height is wrong the shocks may not perform as the designer
> intended, damping
> may vary at the wrong point in the travel, to early or to late, to
> give the
> performance desired.  Given this, how do we know what make/model
> of shock is
> right for a specific Vanagon?
>
> --
>