Why Are Front and Rear Wheels of Trucks or Buses Different?

We see a lot of buses and trucks, especially during intercity trips. These gigantic vehicles, each of which carries cargo or passengers, are also modified from time to time, and we cannot take our eyes off their sparkling looks, whether we like it or not. Now, to you, on buses and trucks (or TIR) we all see but never think why Let’s talk about a difference.

Did you ever pay attention? Trucks and buses The front wheels are curved outwards and the rear wheels are curved inwards.. OK, why? Let’s all illuminate this interesting difference that many of us have not thought about until now.

First of all, let’s remember what buses and trucks look like.

Above, you see a truck without a trailer behind it. If you look carefully; your front wheels convexif the rear wheels concave you see it is. Now let’s see what a bus looks like:

In the photo above, you see the bus. Although the brand and production purpose has changed The front and rear wheels are the same. Let’s take a look at freight trucks.

As you see; Although the vehicle type changes, the design it never changes. So why?

Why are the wheels of trucks and buses not like cars?

Passenger cars, which we prefer as individual consumers, are also available on all four wheels. same way they have rims. You can see a clear example of this in the photo above. However, the situation is different for cargo-oriented vehicles such as buses, trucks and trucks.

As a matter of fact, the front wheel of a car, truck, lorry or bus has the same structure. The rims hold the tire inward. The wheels connected to the axle give direction to the vehicle with the rotation of the steering wheel. All engineering calculations made to date, for vehicles ideal revealed that the rim-axle connection point should be convex. So what happens at the back that we see concave rims on load-bearing vehicles?

The answer is hidden in the double wheel design at the rear…

As you can see in the photo above; almost all vehicles such as trucks, vans, lorries and buses, It has two rear wheels. This is due to the load carrying capacity. Remember: The more axles and wheels a tractor has, the more load-carrying capacity of that tractor is. it increases so much. This is exactly why trucks carrying very large and heavy loads are equipped with many wheels.

As a matter of fact, the answer to the question we are looking for lies exactly here. So much so that the double wheels used in trucks, trucks or buses need to hold together. This is exactly the reason for the design difference. Double wheels used in large vehicles are connected to a single body. Therefore, concave rim design that clings to each other is preferred.

The technical drawing above actually answers the whole question. As you see; coupled together so that the rear double wheels can be attached to the body concave rims needs to be used. Thanks to the dual rim system, a single rim is attached to the body of the vehicle, but thanks to the design, the pressure that comes with the load is shared equally between the two wheels.

So let’s summarize;

The front wheels of vehicles such as trucks, buses and trucks have the same mechanism as passenger cars that we encounter frequently. However, the rear wheel has specially designed rims so that it can be fitted with double tires instead of one and increase the load capacity. So the main difference between the front wheels and the rear wheels is, due to the different design needs required by the number of tires. It can be said that it originates.