AGXs (for a 91 Nissan Sentra (George Roffe)

[George Roffe]

Glen Ho wrote:

>It's probably been about 2 yrs since I've read or wrote anything to this
>mailing list....

Dang.  Been that long?  Good to hear from you again.

>1. I recall the shock dyno posted by Kyle comparing the GAB vs. AGX
>struts.  They clearly showed that BOTH the GAB and AGX were adjustable
>only in rebound - NOT compression.

That was my recollection as well.

>2. Scott, the positive axis shows REBOUND dampening and the negative axis
>is COMPRESSION.  Think about it.  When a shock rebounds, you are pulling
>the piston out of the shock body.  Thus, you measure rebound on the
>*upward* stroke (how much force does it take to pull the shock piston up
>and away from the shock body) as seen on the shock dyno that you
>posted.  When a shock compresses, you are pushing the shock piston *down*
>into the shock body.  That is why compression is measured on the negative
>axis (how much DOWNWARD force does it take to compress the shock).

Actually, just before I left work tonight, I call my pal at Roehrig
Engineering and here's the lowdown of sorts.....

*Generally* the positive numbers indicate compression (I used to call it
jounce, but I found out that's an old expression and not used anymore).  I
say generally since it really depends upon the dyno, or more correctly, the
software.  Also, this is a very old style dyno chart, so who knows what
convention is being used.  Clearly the folks at KYB are FOS though.

If indeed they KYB are compression adjustable instead of rebound
adjustable, then they are cheap crap.  Basically, compression adjustment is
the easy adjustment, but it does the least good (as Scott Higashi already
mentioned).  For a single adjustable damper you want to have rebound
adjustment as this is what will affect and control load transfer.

It is my humble opinion that this chart is actually showing rebound
adjustment.  I've *never* heard of a damper that was compression adjustment
only and no rebound adjustment.  It doesn't make sense.  All of the single
adjustable dampers I'm aware of are rebound adjustable.

>3. Regardless of what the KYB person states, I'd like to ask why ANYONE
>would produce a shock that adjusts BOTH rebound and compression in the
>same direction.

Boy howdy.

>Back to lurker mode.

Come on Glen, we're having an Old Farts Reunion here these days.  Don't
leave now. :-)

George Roffe
Houston, TX
http://www.nissport.com