Tyre Load Distribution

Determination of tyre load distribution

To establish the correct tyre and pressure requirement it is necessary to know the individual axle loadings under normal loaded conditions. Unless you have this information, you are guessing and it is easy to have a 25% pressure error.

The best way of obtaining these masses is either on a weighbridge or by using load scales. Contact your nearest Bridgestone Firestone regional office and our trained personnel will gladly assist you.

If you are unable to weigh your loaded vehicle and provided the unladen axle masses are known, it is possible to calculate the loaded axle mass distribution by using a simple formula.

Determination of the centre of the payload: CPL

It must be assumed that the load is uniformly distributed. Measure the length of the load and establish the half-way mark.

Calculation

A = Distance from front axle (or pivot point) to centre of payload in mm.
B = Distance from rear axle (or axle unit) to centre of payload in mm.
C = Wheelbase in mm.

Distribution of Payload

Proportion of load (rear axle unit) = (A/C) x Payload
Proportion of load (front axle unit) = (B/C) x Payload
Proportion of load per tyre = Load on axle / No. of tyres on axle