hymer BMC 550, Instruction Manual, Page: 26 / 252

3 Before the journey
26
B-MC - 12/18-2 - EHG-0016-01EN
Two simple formulas are needed to calculate the effect of the weight of the
load on the axles:
A x G : R = weight on the rear axle
Weight on the rear axle – G = weight on the front axle
A
= distance between storage space and front axle in cm
G = weight of the load in the storage space in kg
R = wheelbase of the vehicle (distance between axles) in cm

Measure the external distances horizontally from the centre of the front
wheel to the centre of the storage space or to the centre of the back
wheel.

Multiply the distance between storage space and front axle (A) with the
weight of the load in the storage space (G) and divide the result by the
wheelbase (R). The result is the weight of the load in the storage space
on the rear axle. Make a note of this weight and of the storage space.

In a second step, subtract the weight in the storage space (G) from the
weight calculated beforehand. If the result is a
positive value (exam-
ple 1), this means that the load on the front axle is reduced by this
value. If the result is a negative value (example 2), this means that the
load on the front axle is increased . Make a note of this value, too.

Calculate all storage spaces of the vehicle in the same way.

In a last step, add all weights calculated for the rear axle to the rear axle
load and add (or subtract) all weights calculated for the front axle to
(from) the front axle load.
How to determine rear axle load and front axle load is described in sec-
tion 3.2.2.
If the calculated value exceeds the permissible axle load, the load must be
distributed in a different way.
If the load on the front axle is too low, the grip of the tyres on the road is re-
duced (traction). This applies in particular to vehicles with front-wheel drive.
In this case, the load must be redistributed, too.
Example 1 Example 2
Example calculation
Distance to the front axle A (A1) 450 (cm) (A2) 250 (cm)
Weight in the storage space G x 100 (kg) x 50 (kg)
Wheelbase of the vehicle R ÷ 325 (cm) ÷ 325 (cm)
Load on the rear axle
(add to the axle load) 138.5 (kg) 38.5 (kg)
Weight in the storage space - 100 (kg) - 50 (kg)
Load relief to the front axle
(subtract from the axle load) 38.5 (kg)
Load on the front axle
(add to the axle load) -11.5 (kg)
Formulas
Explanation
Calculating axle loads: