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Old October 16th 07, 03:35 AM posted to rec.aviation.soaring
HL Falbaum
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Posts: 133
Default Which Tow Vehicle

OK--I'll supply one.

1999 Chev Tahoe
1999 ASW27 + Cobra
Tongue weight about 9%
all tires new

Begins sway at 68mph--diverging oscillation above 70 mph.
Tried spoilers on vertical fin--no help
Used nails as wedges to stabilize hitch in the receiver--no help.

Attached same setup to a Ford Expedition--stable at up to 110 mph!

Bought 2003 Chev Avalanche
Stable at any speed traffic allowed!

The difference---The 1999 Tahoe had a soft suspension and "vague" steering.
The Avalance and the Expedition are much more stiffly suspended and the
steering more precise. All three vehicles are massive compared to the
Cobra+'27

The answer--IMO the "natural frequency" of the suspension no longer
resonated with the trailer suspension "natural frequency" at highway speed.

--
Hartley Falbaum
"KF" USA


"Dan G" wrote in message
ps.com...
On Oct 12, 3:57 pm, "01-- Zero One" wrote:
So to say that "Towing is simple. Follow these rules, and your rig will
be stable in all conditions and not need stabiliser hitch." is in my
experience a gross oversimplification.


Think we'll have to agree to disagree - but I'd like to know of
examples where these guidelines were met, but the rig was still
unstable.

One thing I don't mention which could be called an
"oversimplification" is weight distribution within the trailer, mass
should be concentrated low and over the axle. However you don't
usually have much choice about that with a glider.


Dan