[Land-speed] Towing a Race car

[Skip Higginbotham]

I agree John, I think it's the location of the pivot point that makes 
all the difference. The distance from the pivot point to the rear 
axle and location relative to the rear axle centerline (fore or aft) 
is also key to reducing sway and the type of sway. Pass a truck with 
a 5th wheel and you get sway and steering effects.....just different 
from a tag trailer if the pivot point is located forward of the CL.
One of the things that has always interested me is that tag trailers 
seem to tend to sway more when going downhill. Why is that? Weight 
shift or deceleration? Ed seems to think deceleration......."sideways 
component".

Skip



At 11:26 PM 6/2/2009, John Burk wrote:
>Ed and Skip , high tongue wt with a 5th wheel hitch is redundant . 
>Tongue wt. isolates sway forces to trailer tires and 5th wheels 
>keeps sway from affecting the steering . But then some people like 
>belt and suspenders . Rear axle weight and sway are separate issues .
>
>
>
>>John/Skip -- I think I share Skip's skepticism.  The physics of the
>>situation suggests to me that the weight on the 5th wheel should be a
>>significant amount to give the rear wheels of the tow vehicle extra
>>sidewise
>>traction to resist the sideways component of trailer deceleration forces
>>whenever slowing down.  With no 5th wheel experience I personally have no
>>good idea of how much down force at the 5th wheel is enough.  But it
>>strikes
>>me that in the case of an 18 wheeler truck that 5th wheel down force could
>>be close to half the weight of the trailer.  And still the truckers have
>>jackknife accidents.  So it seems that the loading of a 5th wheel trailer
>>ought to be as much as the tow vehicle can safely handle considering all
>>aspects of the tow vehicle's operational characteristics.
>>Ed Weldon
>>
>>----- Original Message ----- From: "Skip Higginbotham" <saltrat at pahrump.com>
>>To: "John Burk" <joyseydevil at comcast.net>; "LandSpeed List"
>><Land-speed at autox.team.net>
>>Sent: Tuesday, June 02, 2009 4:42 PM
>>Subject: Re: [Land-speed] Towing a Race car