Technical
To be able to drive off the pavement, off-road vehicles need several characteristics: They need to have a low ground pressure, so as not to sink into soft ground, they need ground clearance to not get hung up on obstacles, and they need to keep their wheels or tracks on the ground so as not to lose traction. Wheeled vehicles accomplish this by having a suitable balance of large or additional tires combined with tall and flexible suspension. Tracked vehicles accomplish this by having wide tracks and a flexible suspension on the road wheels.
The choice of wheels versus tracks are one of cost and suitability. A tracked drive-train is more expensive to produce and maintain. Wheeled drivetrains are cheaper and give a higher top speed. The tracked drive-train has greater off-road capability.
Most off-road vehicles are fitted with especially low gearing. This allows the operator to make the most of the engine's available power while moving slowly through challenging terrain. An internal combustion engine coupled to a normal gearbox often has an output speed too high. The vehicle often has one of two things, either a very low ("granny") first gear (like the all wheel drive Volkswagen Transporter versions) or an additional gearbox in line with the first, called a reduction drive. Some vehicles, like the Bv206 in the picture on the right, also have torque converters to further reduce the gearing.
Many wheeled off-road vehicles have four-wheel drive to keep traction on slippery surfaces. Vehicles designed for use both on and off road may be designed to be switched between two-wheel drive and four-wheel drive so that the vehicle uses fewer driven wheels when driven on the road.
Read more about this topic: Off-road Vehicle
Famous quotes containing the word technical:
“Where there is the necessary technical skill to move mountains, there is no need for the faith that moves mountains.”
—Eric Hoffer (1902–1983)
“The axioms of physics translate the laws of ethics. Thus, “the whole is greater than its part;” “reaction is equal to action;” “the smallest weight may be made to lift the greatest, the difference of weight being compensated by time;” and many the like propositions, which have an ethical as well as physical sense. These propositions have a much more extensive and universal sense when applied to human life, than when confined to technical use.”
—Ralph Waldo Emerson (1803–1882)
“Woman is the future of man. That means that the world which was once formed in man’s image will now be transformed to the image of woman. The more technical and mechanical, cold and metallic it becomes, the more it will need the kind of warmth that only the woman can give it. If we want to save the world, we must adapt to the woman, let ourselves be led by the woman, let ourselves be penetrated by the Ewigweiblich, the eternally feminine!”
—Milan Kundera (b. 1929)