ALKO JOCKEY WITH SCALE

[John_374564913]

I have just purchased an ALKO jockey wheel that measures the nose weight I know how to get the necessary measurements but I am unsure how to do the calculation does anybody know and can they explain in simple terms

below is the calculation I must do

______S x _________Ls
R= ________Kg
________Kr

Thank You in advance

John

 

[Rubix]

John,

Noseweight will just be read directly from your gague.

May I ask what you are trying to work out ?

 

[John_374564913]

in the booklet it says i must do the above calculations because the actual reading at the jockey wheel will not be the actual weight

example 120 reading at the wheel might mean 80 actual that is why i must do the calculation

regards

john

 

[ProfJohnL]

Hello John,

The reason you need to do a calculation is because nose load is force acting at a distance from the main axle, and the jockey wheel is a different distance, and that act like levers. The longer the handle the easier it is to lever a weight. The actual hitch is further away from the axle than the jockey wheel

It down to a process called turning moments, force time distance and its relatively simple to do.

I’m not familiar with ALKO jockey wheel system, but the principal will be the same.

You need to make two initial measurements with a tape measure.

L1 = distance from the core of the jockey wheel stem to the middle of the axle
L2 = distance from the hitch to the middle of the axle

L1/L2 = A correction factor. This is the correction factor for your caravan, and it will not change. Keep a note of this value as you will need it every time you use the gauge.

To apply it:
This must be done on a level (horizontal) surface
load your caravan, and hitch it to the loaded (passengers and luggage) car. Note how high the hitch is from the ground.
Uncouple the car, and using the jockey wheel set the hitch to the same height as when it was coupled.
Now read the load on the jockey wheel. Multiply the reading by the correction factor to calculate the actual nose load at the hitch.
If necessary re trim the caravan and repeat the measurement process.
Just a note of warning. The accuracy and consistency of the Alko device is not known, so it is wise to compare it to some other device like a pair of bathroom scales. When checking with scales, make sure the jockey wheel is at right angles to centre line of the caravan so the point of contact with the scales is the same distance from the axle as the stem of the jockey wheel.

 

[John_374564913]

Dear Prof

Thanks for the reply the calculation required is as follows after reading the book carefully and having read your explanation
Max figure for my car is 82.4 kgs that equals R /S

Distance from my wheels to hitch = 455 cm =Ls

Distance from jockey wheel = 400cm =Lr

hence 82.4 x 455 divided by 400 = 93.73 kgs on the jockey wheel guage.

before hitching the caravan I will of course double check with another form of measurment

regards

John