John,
Your theory may be correct. I have experienced some very hectic trips
because of trailer whip. Usually this is magnified when going downhill.
I remember when the tandem trailers were first being used by Bonneville
racers. There were some horror stories, like towing from LA to the Salt
@ 35 MPH. A few lost race cars and trailers. This was a problem that was
not experienced with single axle trailers.
I have tried moving weight forward which usually has helped control the
whip. The thing that I did most recently was to purchase a hitch insert
that raised the tongue. My theory now is that the whip is caused by
uneven loading on the tandem axles. We still carry quite a bit of weight
on the hitch, but we tow at 75 MPH plus without a problem.
Tom, Redding CA - #216 D/CC
John Burk wrote:
> It occurred to me what causes the trailer sway cycle - The tail of the
> trailer sways to the right , the trailer becomes a lever with the trailer
> tires as the fulcrum - The hitch is pushed to the left - The truck becomes
> another lever with the rear tires as the fulcrum , the front is pushed right
> and the caster in the front axel makes it steer slightly that way (opposite of
> what would stop the cycle) - If the trailer CG is more foreword it's tires act
> less like a fulcrum and if the truck has a fifth wheel hitch it no longer is a
> lever and the front steering sees no side load - I CLEARLY remember my trailer
> using up 3 lanes of the Pennsylvania turnpike while the 18 wheeler I had just
> passed scrambled to get out of the way .
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