When it comes to hard-core off-roading, people often see a boxy vehicle wrapped in mud on a variety of non-paved roads.
The reason why they have such ability has a lot to do with their hard equipment. A set of MT tires with excellent grip is an essential element of the hardcore, a four-wheel drive system is also indispensable; a differential lock is an artifact for escaping the trap, which the hardcore off-road vehicle must be equipped with; and the most critical element is the body structure with girders. Until now, whether the body has a girder or not has been regarded as the most critical element in judging whether a car is hardcore.
So, why do hardcore off-roaders need girders? How does it directly help with the improvement of off-road performance? Next, let's take a closer look.
In fact, there is no such thing as "girder" in professional terms, and the body with girder is called a non-bearing body in professional terms. Because this non-load-bearing body has a trapezoidal beam as a frame to bear the weight of the vehicle, so its body structure does not need to bear too much force, then the body is more like a shell buckled on the chassis, even if there is no body, the vehicle can still run normally. The other structure is called the load-bearing body, which is mostly used in cars and urban SUVs.
So why are non-loader bodies favored by hardcore off-road vehicles? The main reasons are the following two points: first, the non-load-bearing body can achieve higher torsional strength at a lower cost; second, the non-bearing body has a higher ground clearance, which can greatly improve the performance of off-road vehicles.
Let's explain the first point first. The frame of the non-load-bearing body is usually composed of two longitudinal beams and several beams, of which the longitudinal beam is mainly responsible for resisting the bending deformation of the vehicle, and the beam is mainly responsible for resisting the torsional deformation of the vehicle. Because the bending stress in the middle of the vehicle is large, the longitudinal girder of the non-load-bearing body structure usually adopts a variable diameter design, that is, the middle of the longitudinal beam is the thickest, and the diameter of the front and rear longitudinal girder will be reduced to play a role in weight reduction.
Because hard-core off-road often drives on the road very poor non-paved road, this road has a very large impact on the vehicle, if the body strength is not enough, then over time, the body is easy to cause metal fatigue to appear abnormal or even deformed, and then affect the vehicle off-road performance. And this kind of frame welded with steel, although the process and material are relatively simple and cheap, can obtain very high torsional strength, even if it encounters high-strength off-road sections, this steel frame can also cope with it freely. However, if the road conditions are too extreme, the non-load-bearing body is not easy to make.
However, this steel frame also has great drawbacks, that is, the strength of the frame is too dependent on steel stacking, which makes the weight of the vehicle using non-bearing body structure will rise significantly, and the weight of the vehicle is a major disadvantage in the off-road process, and many trapped cars or can not successfully pass the obstacle are because of excessive weight. It is precisely because of this drawback that modern hardcore off-road has begun to use another body structure, the specific content of which we have expanded in detail in the later "Uncle Che Lecture Hall".
Next, we look at the second advantage of the non-load-bearing body, the non-bearing body has a steel welded frame as the chassis, and the suspension, wheels and other structures are installed under the chassis, so the vehicle chassis will be passively raised at this time. While the minimum ground clearance is still determined by the lowest point, the lowest point of the hardcore off-road vehicle is often a very strong component such as the rear axle differential housing, which will not lose anything even if it collides with the rock. Of course, if the speed is too high and the collision occurs, even the strongest structure will be seriously damaged.
For friends who pursue extreme rock climbing, in order to increase the height of the vehicle chassis as much as possible, you can also choose to install a door bridge suspension, which must be combined with the non-bearing body structure to be installed, so the structural advantages of the non-bearing body are once again reflected. The door axle suspension with the wheel side reducer can reduce the working pressure of the rear axle differential, thereby greatly reducing the size of the rear axle differential, and the half-shaft height of the wheel will also be greatly improved at this time, so the vehicle chassis height will be further improved. After the chassis is raised, the vehicle passability will naturally be improved as it should be.
It is precisely because of the above two main factors that the non-load-bearing body has become the darling of hardcore off-road vehicles.
Uncle Che summed up
Through the detailed introduction, we can see that the reason why the non-load-bearing body can become the standard of hardcore off-road vehicles is directly related to its powerful performance and is also directly related to its super high cost performance. Although this body structure can play a role in improving the ground clearance, this limit increase is limited to a very small number of off-road enthusiasts, and for the vast majority of people, they are more concerned about the strength of the non-bearing body. But with the advancement of science and technology, even without the use of girders can create a very strong body, but the cost is slightly higher, so the hardcore off-road and girder may also have to say goodbye, the specific content we will expand in detail in the later article.