Question

have you wondered why some trucks has double axles and some dont?

Answer 1

Answer:

Trucks and Buses are commonly seen in our daily routine and we all have questioned ourselves but often failed to reason out that why these vehicles have dual tyres at the rear axle and single tyres at the front axle.

Well the vehicle’s overall weight is distributed between the two axles. The Front Axle mostly takes the load of the engine only, whereas the Rear Axle has to take the load of the cargo in case of trucks and additional load of passengers in case of buses. So dual tyres have been used to increase the load capacity

The major load of the vehicle is on the rear axle, so in order to maintain the ground pressure between certain limits, it is required to increase the contact patch area of the tyres on rear axle which finally gave birth to usage of dual tyres in rear axle. This can be understood from the simple formula of PRESSURE=FORCE(load)/AREA (Pressure reduces as the contact patch area increases).