Date: Thu, 2 Jul 1998 00:32:37 -0700
Reply-To: "Steven X. Schwenk" <sxs@SCHWENK-LAW.COM>
Sender: Vanagon Mailing List <Vanagon@vanagon.com>
From: "Steven X. Schwenk" <sxs@SCHWENK-LAW.COM>
Subject: Re: spacers and sproings (THIS ONE corrected formatting)
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Nat,
Thanks for the support and insight. I was beginning to think that no
one could understand a word I was saying...which would obviously suggest
that I had better take a look in the mirror. I think one problem is my
obvious misuse of termonology, which endlessly upset and confused the
engineers out there :~), and understandably so. sorry.
Still, my goal isn't/wasn't to write a correct disertation on the
physics of springs, but to tune the suspension on my van, and hopefully
improve it. That's where the bike experience is quite valuable. I may
not be able to describe the physics involved, but I know how to apply
them, and have many times...on a weekly basis for months on end during
racing season. I find it interesting that you understand what I am
trying to do and, like me, you have actual experinece tuning
suspension. >From what I see in there, this is possible. It will be a
pain in the sas since we do not know what the optimal sag is on the
syncro westfalia. I would guess that 30% is a good starting point, but
we have to find it...which probably means pulling the springs numerous
times to get it right...i.e., finding the optimal sag, and then
adjusting each wheel to that sag. I hope to get it pretty
precise...assuming I do not have to pull the springs 10 times. We'll
see how it goes. Any tips on simplifying/speeding-up spring removal or
best compressors to use?
steve
Nathaniel Merrill wrote:
> Steve,
> I have been watching this argucussion for a while as I am interested
in suspension topics in general. What you have said here is clearly
what needs to be said, however it also clearly elucidates what must be
asked....
> Your motorcycle description below is correct (I have extensive
experience as well). You are increasing the springs Preload to
accommodate a heavier rider---in order to achieve the proper SAG. This
is important. You want to be able to control the sag for the ride
quality you want. The sag must be within a specific range for
suspension performance to be optimal. Preload adjustment works here
because the resistance from the spring to compression is progressive
(linear or not) so preloading alters the starting point. But you must
have a spring with approximately the right rate in the first place
because preload adjustment only goes so far either way. To much and the
spring rate is so progressive that the ride is overly harsh (because the
rate increase is exponential). <<<snip >>>
> Feel free to post this IF it makes sense.
>
> Nat
> Seattle
>
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