Date: Fri, 9 May 2008 10:08:33 -0700
Reply-To: Don Hanson <dhanson@GORGE.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Don Hanson <dhanson@GORGE.NET>
Subject: Re: DIY alignments
Content-Type: text/plain; charset="Windows-1252"
Again, Oh Hi, bye the way, again, a lot of interpendent variables come
into play when you talk about any one specific suspension and alignment
question.
Without knowing the exact suspension geometry of the vanagon, I couldn't
say for certain what the effect of bigger or smaller tires might be, let
alone how to improve a deficit like you describe. I'd guess you'll have a
combo of factors contributing to the poor handling characteristics you
describe. A big portion could be 'Tire-specific" rather than tire size
specific.
When you say "taller than stock" size tires...the vanagons already have
very tall tires..tall in cross section..and are supersensitive to tire wall
stiffness, which causes just the behavior you describe if you have too
'floppy' sidewalls on a tall tire... I don't see you correcting the
behavior you describe very much with alignment changes, unless you have
something pretty far out of spec already.
Look at it like this: If your wheels and tires were absolutely
solid..simply increasing the diameter of package would not have too much
effect on the alignment settings..Total oversimplification, of course..Once
the suspension starts compressing, the wheels are turned from straight ahead
, you brake, shifting weight and Center of Gravity to the front, etc etc
etc...everything changes in relationship to every other thing..and moving
the tire contact patch further away from the center of the suspension
load...the wheel spindles..You will be changing some of the ratios...
Sheesh! Its too complicated to 'simplify' for the list..
Just for an experiment, I will soon be adding some caster to my settings
to try to 'calm down' my van's cross-wind sensitivity..It probably won't do
much, and there will be negative consequences. The factory specs are the
best 'average driver' suspension settings that the engineers could come up
with, so you won't be doing much improving on a near stock vanagon's
alignment by tweeking it..
Don Hanson
Date: Fri, 9 May 2008 09:16:21 -0400
From: Doug Fitz-Randolph <fitzr@SUSCOM-MAINE.NET>
Subject: Re: DIY alignments
Hi Don,
You - and others - have mentioned that proper alignment is influenced by
tire size. What sort of changes to alignment specs would be dictated for
significantly taller-than-stock tires? Some people (I) have experienced
poor tracking/stability, especially in crosswinds, with larger tires. It
seems like caster would need to be increased if poor tracking was the
complaint.
Thanks,
Doug Fitz-Randolph
Freeport, ME
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