Artificial unevenness on the road is even more dangerous for the car’s suspension than a pit: when it hits a pit at speed, the suspension responds to rebound, and when it hits an obstacle, it compresses.
When and where did artificial bumps appear on the roads, what requirements does the law impose on them, and most importantly — how to reduce the load on the suspension when passing speed bumps? We disassemble from a technical point of view.
Nobody needs to explain what “speed bumps” are. Even at the dawn of the 20th century, American farmers began to lay across the roads, halved along the logs. The rapid development of the road network and the personal car as a phenomenon provoked the appearance of a huge number of people who want to take it with a breeze. Often such reckless drivers ended up very poorly — in the side of a cow peacefully crossing the road. Of course, they also put warning road signs, but who were they interested in — what then, what now? A log on the road, forcing even the most inveterate «rider» to slow down, worked unequivocally more efficiently. Well, the state, quickly realizing the need for such funds, has already regulated the installation of «loungers» by law.
It is noteworthy that the first official speed bump on American roads dates back to 1906 — a couple of years before the appearance of the most mass-produced Ford «T» model. An artificial asphalt hill 13 cm high on one of the streets of Chatham (New Jersey) forced too dashing horse-drawn carriages to slow down.
In Russia, «artificial irregularities», as this simple design is officially called, appeared around the beginning of the two thousandth. The peculiarities of national roads often led (and still lead) to very comical situations: money for the installation was allocated, the work on installation on the road was somehow carried out, but there were no special roads — as in the photo above.
Nevertheless, even for this seemingly primitive structure, there are a bunch of normative points and subparagraphs of GOST.
There are many more provisions, but the reader will hardly be interested in listing them. We all understand perfectly well that «lying», as well as roads that fully comply with GOST, even in Moscow will have to look for the day and with a flashlight. But a kind of workshop will be more useful.
Obviously, the IU is no less dangerous for the car suspension than a pit. The difference is that when hitting a hole at speed, the suspension is triggered by
Let’s try to present the situation in an abstract way: the wheel «hanging» in the pit acts on the suspension only with its mass and rebound inertia (given by the spring). But when the front suspension is compressed and rests against the travel stop at speed, several hundred kilograms of mass of the heavy front end of the car impact on several small points. One «successful» speed bump is enough to break through or bend the shock absorbers, break the thrust bearings, and in the case of old tired cars — and get hold of cracks in the supporting shells of the body.
But even at low speeds, the speed bumps must be passed correctly. And the same inertia and mass of the car will help us. Only now are we using them for the purposes we need.
If we describe the algorithm in a couple of steps, we proceed as follows:
Thus, the weight of the vehicle itself and its inertia help the wheel going uphill: it removes a part of the load from the front suspension, and the drive onto the engine takes place very smoothly. Of course, this method requires some skill and practice, but very soon you will learn how to pass artificial obstacles comfortably and almost painlessly for suspension.
The photo below shows the moment of the correct entry into a speed bump. The body of the car is parallel to the road, which means that there is no forward peck — the brake was released right before driving over the obstacle. Consequently, the front suspension is not overloaded by the weight of the vehicle and will not experience an impact. If you hold the brake even at the moment of arrival, the recumbent will hit the already loaded and compressed suspension. As mentioned above, this is fraught with breakdown and a strong impact on the body. And it does not add comfort.
And the recumbent ones can act as a completely visual indicator of the state of the suspension elements. If you enter the phrase “
And a few words about the “diagonal” passage of artificial obstacles, which was so popular in the mid-2000s. For some reason, it was believed that if you pass the IN obliquely, the suspension gets less, and the process itself becomes more comfortable for riders. As for the second — under certain conditions, this is true. If the car’s suspension is soft enough, then the successive «roll» over an obstacle with all the wheels in turn is really smoother than the «bounce» first by the front axle and then by the rear axle.
But this does not prolong the suspension resource at all, but rather even
By the way, you can still remember one general rule: the wider the speed bump, the higher the speed of his travel you can afford. Again, within the framework of common sense.
In conclusion, it can be noted that the use of artificial obstacles of the «speed bump» type in itself is unambiguously justified. Such a measure is incomparably cheaper than a camera or a patrol outfit, but it is clearly more effective: no matter how cool the reckless driver is, even the most sophisticated numbers and ksivs will not save the suspension from physical damage. Whether you want it or not, you will slow down the speed.
Another thing is that the most sensible idea with good intentions in our realities, alas, often turns into another obstacle to normal traffic. But that’s a completely different story.
Photos are taken from open sources.