Re: [SilverStreak] no "need for levelers or sway bars"

[<waymark1@xxxxxxxx>]

The main thing weight distribution spring bars do is put part of the tongue 
weight on the front wheels of your tow vehicle. On a 1T pickup the springs 
are so stiff that nondistributed tongue weight doesn't appear to do much to 
the attitude of the truck, but it does lever weight off the front tires. 
This reduces steering and front braking effectiveness. 
The longer the tow vehicle wheelbase, the less effect tongue weight has on 
tow vehicle front axle loading.
The longer the distance the tow ball is behind the rear axle of the tow 
vehicle, the more effect tongue weight has on tow vehicle front axle loading.
The spring bars of a weight distributing hitch shift part of the tongue 
weight otherwise on the rear wheels of the tow vehicle to the front wheels 
of the tow vehicle and part to the trailer wheels.
Ideally a drive-on scale is used to weigh each pair of wheels of the tow 
vehicle and the weight on the wheels of the trailer. A platform scale that 
has approach ramps that are level with the scale platform is required.
1) Unhitch the trailer. Drive the front wheels of tow vehicle, loaded as it 
will be when towing, onto the scale. Record the weight.
2) Drive the tow vehicle forward so it is entirely on the scale platform. 
Record the weight - this is the total weight of the tow vehicle.
3) Drive the tow vehicle forward so the rear wheels only are on the scale. 
Record the weight.
4) Hitch up the trailer and pull it forward until the tongue is over the 
scale platform but the trailer wheels are not on the platform. Unhitch the 
trailer and pull the tow vehicle off the scale platform. Record the weight 
on the tongue of the trailer. What you need is the weight on the center of 
the hitch ball socket of the hitch coupler. Setting the tongue jack on the 
scale is close enough.
Part of this weight will be shifted to the front tires of the tow vehicle and 
to the tires of the trailer.
5) Hitch up and pull the trailer forward until the trailer tires are on the 
scale platform. Record the weight on the trailer tires.
6) Hook up the weight distribution spring bars and tighten the chains to a 
guess as to what they should be. 
7) Back the combination until the front tires of the tow vehicle are on the 
scale alone. Record the weight. The desired weight is the weight recorded in 
(1) plus an additional load in the same proportion to the dead tongue weight 
(4) as the weight on the tow vehicle front tires is to the weight on the tow 
vehicle rear tires.
8) Pull forward until the rear tires only are on the scale platform. Record 
the weight. The desired weight is the weight recorded in (1) plus an additional 
load in the same proportion to the dead tongue weight (4) as the weight on the 
tow vehicle rear tires is to the weight on the tow vehicle front tires.
If your WD hitch has chains the adjustment won't be precise. With a little 
experimentation you can get close. With screw-adjusting spring bar tensioners 
you can get right on.
9) Pull the combo forward until only the trailer tires are on the scale. This 
weight must not be over the load rating of the axles and tires. If it is, the 
weight of the trailer must be reduced. We'd like for the loading to be no more 
than 80% of the rated loadings but in the RV world this is an ideal often not 
achieved.
Weigh everything (except the tongue weight) again and inflate the tires according 
to the tire manufacturer's load/pressure chart. This is supposed to make for an 
even loading across the width of the tire patch on the road. The tread will wear 
flat if the pressure is correct for the load. Too much pressure for the load and 
the tire will wear in the center faster. Too little pressure for the load and the 
tire will wear on the shoulders faster. It is better to err on the side of a 
little too much pressure than too little pressure. High pressure increases the 
tire's resistance to side sway. It also increases adhesion to the pavement up to 
a point where the shoulders of the tread are beginning to lift from the pavement. 
Also excessively hard tires are "bouncier," which can cause the tire to lose 
adhesion by "chattering" on rough spots, "washboarding," potholes, in the road.
Never increase pressure above the rated maximum pressure of either the tire or 
the wheel. It does not increase the safe load capacity of the tire.

The combination should be stable without sway controls on the road up to the 
maximum speed allowed (65 mph for ST tires; 75 mph for LT tires) in open road, 
no wind, no passing trucks conditions. Sway controls are for resisting sway induced 
by side-wind gusts, passing large vehicles, and flat tires, not for countering poor 
trailer design or loading, mismatched tow vehicle-trailer combinations or sloshing 
wastewater in partly-filled holding tanks. Holding tanks should have no more than a 
gallon or two each just to keep residues wet.

Bet that Argosy motor home had a lot more rear overhang than the truck?

Al

-- Jason Parks <jjparks@shaw.ca> wrote:

Thanks all for replying, it's great advice. I will add to my list to 
investigate weight distribution bars as my rig is sagging. In the meanwhile I'll 
upsize my tanks to at least a #20 bottle if not bigger. Jason

----- Original Message ----- 
From: "Eddie" <Eddie@Huffstetter.com>
To: <sslist@tompatterson.com>
Sent: Tuesday, March 11, 2008 8:49 AM
Subject: Re: [SilverStreak] size of propane tanks

> Jason,

> Depending upon your tow vehicle, there are two things that can really add 
> to stability in towing, even when the tongue weight is correct. Those two are 
> load levelers sometimes called stabilizers, and the other is anti-sway bar, or 
> two bars depending on length and weight. Usually only one is needed, not 
> expensive and really works great. Those two things are great tools.
>
> I use a F350 diesel dually crew so I never have had any trailer give me 
> need for levelers or sway bars, but I did need sway bars to tow a 32 foot Silver 
> Streak out of the Great Lakes. Absolute must, the tow vehicle was a 78 Argosy 
> motor home, certainly heavier than my truck, and the same number of wheels, but 
> the wind from the motor home created a draft environment on the trailer that was 
> destroyed with every passing truck. The tow was impossible to control above 45 
> mph and the sway bar was mandatory. So there are a lot of factors that can affect 
> towing and the equipment you may need. The important thing is don't find out the 
> hard way.
> -Eddie-
> Houston, TX