I was going up to get my van weighed today and had debated in my mind whether to take the weight distribution hitch out of the boot and fit it or
just use the std goose neck as the w/bridge is only around the cnr. Then it occurred to me that I'd have to unhitch it once on the weigh bridge, in order to weigh the van , and not the car at the same time
( I weighed the car last week on its own after I had alum body fitted ) .
I dont understand the physics apart from the fact that the WDH transfers weight to the cars front wheels .
Does it actually transfer more weight than normal TBW onto the car or less . On the tow ball I'd expect less but to the vehicle overall more ?
Just from memory & that's a risky thing for me to do at my age, but I seem to recall that the TBW stays the same but some of that weight is taken off the rear wheels of the tug & transferred to its front wheels. This also has the effect of lifting the rear of the Tug.
From the HR site ....
Understanding Weight Distribution and Sway Control
Weight Distribution
When a caravan or trailer is connected to a vehicle, there is an inevitable addition of weight to the rear of the vehicle. The added weight can alter the handling of the vehicle due to the imbalance of weight from the front to the rear.
This can pose serious safety concerns, especially at high speeds. Less weight over the front axle reduces braking efficiency and steering control, and combined with the added weight at the rear, can cause the vehicle to lose control. Additionally, head lamps are thrown out of alignment and fuel use & tyre wear can dramatically increase.
Weight Distribution Hitches have been designed to address these problems by restoring even balance across all axles of the vehicle and trailer. Their aim is to enable the vehicle to be driven at the maximum legal speed while not compromising on safety.
Weight Distribution Hitches work by changing the point at which the load of the trailer is transferred to the vehicle. Traditionally, the entire towball weight of the trailer is transferred and carried at the tow ball, as shown in Diagram 1. Weight Distribution Hitches correct this by redistributing the weight across all axles of the vehicle and caravan (as shown in Diagram 2), much like the lifting action of a wheelbarrow.
Hayman Reese Weight Distribution Hitches have been designed & engineered to ensure towing vehicles operate at their optimum braking, steering and general driving capacity. Available in a range of sizes and weight specifications, Hayman Reese Weight Distribution Hitches help you stay safer on the roads.
Get weights for each axle both with and without the WDH in place. Then weigh the lot with the van unhitched from the tug. You should be able to produce a table like this one.
That is a demo that was given at a Melbourne caravan show. Do a bit of fiddling with the figures and see how things change with and without WDH (including the vans axle.)
Just be careful if you get pulled over by Highways,
The HR system could put too much weight on front axle .
Take the bars off first (loosen chains) so you get
TRUE axle loadings.
Unless you iffy of course.
Combined fine. BUT axles iffy. (My rig with water in tanks)
Imagine the towbar, ball and coupling are one rigid unit. If you lift up on the back of the van, (theoretically) the whole van and the back of the car rise into the air, pivoting around the car's front wheels. Now let the van down again, and assuming the combination is on level ground, the weight at the front is distributed evenly across the car's wheels. (Of course, it'd be hopeless for towing as you couldn't turn or go over a spoon drain.)
Now let the coupling be free without any WDH. Lift up on the back of the van, and the van rises, putting much of its weight on the ball which pivots and pushes the back of the car down causing the front wheels to rise. Keep lifting and the front of the car will be lifted off the ground, (unless the back end touches down first).
A WDH is a compromise between these two extremes. It increases the rigidity of the coupling, but leaves it free enough to cope with bumps and turns. The flexibility is due to the flexible bars and chains. Now if you lift up on the back of the van, the pivoting of the coupling is resisted (but not completely prevented) by the bending of the bars, leaving more of the weight on the front wheels.
Imagine the towbar, ball and coupling are one rigid unit. If you lift up on the back of the van, (theoretically) the whole van and the back of the car rise into the air, pivoting around the car's front wheels. Now let the van down again, and assuming the combination is on level ground, the weight at the front is distributed evenly across the car's wheels. (Of course, it'd be hopeless for towing as you couldn't turn or go over a spoon drain.)
Now let the coupling be free without any WDH. Lift up on the back of the van, and the van rises, putting much of its weight on the ball which pivots and pushes the back of the car down causing the front wheels to rise (pivoting around the back axle). Keep lifting and the front of the car will be lifted off the ground, (unless the back end touches down first).
A WDH is a compromise between these two extremes. It increases the rigidity of the coupling, but leaves it free enough to cope with bumps and turns. The flexibility is due to the flexible bars and chains. Now if you lift up on the back of the van, the pivoting of the coupling is resisted (but not completely prevented) by the bending of the bars, leaving more of the weight on the front wheels.
That's how it works...
C00P
-- Edited by C00P on Monday 22nd of August 2016 10:04:56 PM
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