Benutzer:Lothar Gerlach/Offroadfahrtechniken
Off Roading is a recreational pursuit popular among a sub-section of the owners of four wheel drive or all-terrain vehicles. The term "Off-Road" refers to a driving surface which is not conventionally paved such as sand, gravel, riverbeds, mud, snow, rocks and other natural terrain. These terrains can sometimes only be traveled by vehicles designed for off-road driving (such as heavy-duty trucks and equipment, SUVs, ATVs, snowmobiles, motorcycles, mountain bicycles) or vehicles that have extra ground clearance, sturdy tires, and in some cases, front and rear locking differential. Notable examples of vehicle manufacturers that produce a type of off-road vehicle (ORV) include AM General, Land Rover, Ford, General Motors, Dodge, Jeep, Toyota, and Volkswagen.
Types of off-roading
There are numerous categories of off roading, with something suitable for all levels of experience and equipment.
Some of the major categories of off roading are listed below.
Duneing
Duneing involves driving over sand dunes, frequently associated with tourism in the Middle-East. There are also many state parks in the United States that allow ORV's to drive on them, including the Silver Lake Sand Dunes in Michigan and the Glamis Sand Dunes|Gordons Well in California.
Greenlaning
Greenlaning or "Two-tracking" is one of the least 'extreme' categories. It is generally suitable for any four wheel drive vehicle, even with factory tires and equipment. The term greenlane refers to the fact that they routes are predominantly along unpaved tracks, forest tracks, or older roadways that may have fallen into disuse. For a lot of greenlaners, the main emphasis is on enjoying the countryside, and accessing areas that may be seldom traveled by motor vehicles, rather than exploring the performance envelope of their vehicle.
Mudding ( or Mud Bogging )
Mudding involves finding a large area of wet mud or clay and attempting to drive as far through it as possible without becoming stuck. Usually, the stock tyres supplied with four by four vehicles are completely inadequate for this type of off roading, and Mud-terrain tyres are required. Strongly attached recovery points are also recommended to enable the vehicle to be towed out when it becomes bogged down. Next to traction, momentum is a big factor in success.
This activity has a competitive form known as Mud bogging.
Rock Crawling
Rock crawling is a highly technical category of off roading. Vehicles are typically modified with larger than stock tires, suspension components that allow greater axle articulation, and changes in the differential (mechanics) gear ratio in order to provide the ideal high torque/low speed operation for rock crawling to traverse obstacles. It is quite common for a rock crawler to have a spotter - an assistant who will go on foot alongside or in front of the vehicle to provide information to the driver on obstacles or areas of terrain that the driver may be unable to see.
Rock Racing
Rock Racing is very similar to Rock crawling in the fact that the vehicles are driven over rocks, the difference is that there are no penalties for hitting cones, backing up or winching as is done in rock crawling.
Trials
Trials are probably the safest form of motorsport. All progress is made at low speed, and the emphasis is on skill rather than finishing first. However, trialling can be highly competitive. Trials take many forms, but the most common in the UK is the club trial. An area of land (often farmland or woodland - with permission - or a disused quarry) is set out with pairs of garden canes. Each pair of canes is placed just wide enough to get a standard vehicle (usually a Land Rover) through without touching. Ten pairs of these canes are set out, and the competitors drive through them one at a time. The person setting out the course will normally attempt to make driving between and through the gates very difficult, by including side-slopes, steep hills, water and mud holes, rocks and strategically-placed trees in the course. The object is to drive through the canes without touching them, or allowing the vehicle to stop. Ten gates make a "section", and a day's sport might include six or seven sections, driven by between five and fifteen vehicles. The object, obviously, is to end the day with as few points as possible. Vehicles vary from standard road-going 4x4s to wild and highly modified vehicles which can seemingly go anywhere. Driver skill is at a premium, as old Series Land Rovers can often be seen beating modified and specialised vehicles costing thousands of pounds.
Winch Events
Winch events often involve attempting to access areas that would be impassable without the use of a winch - this can include traversing deep gullies, steep slopes and so on. Most off road vehicles that have been prepared for this type of event will typically have two winches, one at the front and one at the rear of the vehicle, each with a rated pull of over 9,000 lb.
Off-roading Events
In some countries, off-road activities are strictly regulated, while others promote cross country off-road endurance events like the Dakar Rally and Baja 500 & 1000 that are considered a test of navigation skills and machine durability. Off road parks also host a number of events as it might be the only legal place to off-road in the area. Some different events include Jamborees, Rock Crawling competitions, Mud Bog races, Top Truck Challenges, Sand racing as well as many other events.
Off-roading Organizations
Due to the extreme criticism of the sport of off-roading, many organizations and associations have been formed to show a united front in the battle to keep public lands open to off-roaders. Some organizations such as the Blue Ribbon Coalition and Tread Lightly! are not off road clubs at all and are solely set up to fight land closures and to promote environmentally friending off-roading.
Vehicle modification
While many off-road vehicles can greenland or "two track" most unpaved roads. The desire of many off-roading enthusiasts is to attempt much more challenging terrain. The following listings show the modifications that are done and why:
Vehicle lifts
A vehicle lift is when the normal height of a vehicle is lifted to increase the amount of clearance between the ground and the bottom of the body or frame of the vehicle. There are numerous types of vehicle lifts:
Body lift: A simple and cheap way to lift a vehicle that has a body on frame design such as a pickup truck or some SUVs. A body lift consists of larger spacers that replace the normal mounting points of the vehicle's body on its frame. These typically are between 1 - 4 inches. Any more than four inches will create a less sturdy set up. Body lifts are not possible on vehicles with a "Uni-body" construction. Uni-body vehicles have the frame formed into the body, such as on a Jeep Cherokee.
Suspension lift: A suspension lift is when modifications are done to the vehicle's springs, shocks, controlling arms and steering linkage. In this case small or short pieces of the suspension are replaced with longer or larger items of similar construction. Lifting a vehicle changes it's driving dynamics and a suspension lift adds to the vehicle's handling capabilities in relation to the increased height (see lifting concerns below).
Some examples of this are:
- Larger arced Leaf springs
- Longer Coil springs
- Coil spacer blocks
- Leaf spring spacer blocks
- Longer Control arms
- Longer Pitman arms
- Air bag spring replacement
- Longer leaf spring shackles
- Reverse leaf spring mounting on the axle
- Longer Spindles in the front
Large tires
A quick and easy way to gain ground clearance is to increase the size of the tires on a vehicle. One advantage over body and suspension lifts is that larger tires will improve ground clearance under all parts of the vehicle, including the axles and differentials - typically the next lowest points after the tires. While some vehicles can have larger tires added without a lift kit, such as a Ford F-250/F-350 pick-up trucks, most will require a lift kit in addition to larger tires, and in some cases bodywork modification (cut back wheel arches) may also be necessary.
Many off-roaders will combine different aspects of each of these vehicle lifting techniques, with the more experienced combining all of these items for a vehicle that could be lifted over 12 inches from its normal ride height
Traction control
One of the main aspects of off-roading is to be able to keep traction on different obstacles. This can be done with more aggressive tread on tires as well as with help from traction control devices in drivetrain.
Some traction control devices used are:
- Locking differential
- Lowered Gear ratio
- Limited slip differential
- Four-wheel drive
- 'Airing Down' - greatly lowering the air pressure in the tires
Dangers of vehicle lifting
While lifting a vehicle to gain ground clearance is helpful to off-roaders it can also make a vehicle dangerous because when a vehicle has been lifted its center of gravity rises making the vehicle more likely to tip over in certain situations. Other dangers are loss of visibility of smaller objects and bumper height as compared to other vehicles on the road. In the United States bumper and frame height laws are in effect in most states to make sure that the vehicles on the road are not too much higher than their car counterparts.
Off-roading in popular culture
Music
- C.W. McCall's works include at least two songs about the pastime, "Four Wheel Drive" and "Black Bear Road."
- 2Pac and Dr. Dre's song California Love contained off-roading scenes.
- Alan Jackson's song Summer Time Blues has many vehicles off roading in it.
- DMX has used all-terrain vehicles in his videos.
- Gretchen Wilson's song Redneck Woman begins with her and friends mud plugging.
Movies
- Cannonball Run had scenes of Jackie Chan's vehicle off-roading and joining a baja in progress.
- From Dust to Glory is a movie about off-roading the Baja 1000.
- Mad Max 2: The Road Warrior contained many scenes of vehicles off-roading.
- Ace Ventura Jim Carey drives a Landrover through the jungle demolishing it on the way.
Television
- The Fall Guy TV show had a modified GMC Pick Up off roading throughout the show.
- Four Wheeler TV on The Outdoor Channel.
- Trucks! show on Spike TV about modifying trucks.
- Xtreme 4x4 show on Spike TV about modifying 4x4's and off-roading events.
Criticism of ORV use
Environmental impact
Off-road vehicle use on public land has been criticized by the U.S. government[1] and prominent environmental organizations including the Sierra Club and The Wilderness Society[2][3].
The U.S. government and other organizations have noted several consequences of ORV use such as pollution, trail damage, erosion and land degradation which may leave hiking trails impassable. In one instance in Duluth, MN, the estimated cost to stop erosion and restore safe walking access on trails was estimated at $81,000[4].
According to the U.S. Forest Service, the use of the two-stroke engine (common in vehicles designed specifically for off-road use) also causes concerns about pollution and contamination, because "two-stroke engines engines emit about 20 to 33 percent of the consumed fuel through the exhaust" and "discharge from two-stroke snowmobile engines can lead to indirect pollutant deposition into the top layer of snow and subsequently into the associated surface and ground water."[5].
Noise pollution is also a concern to environmentalists[6]. Several scientific studies conducted by Montana State University, California State University, University of Florida, and others, have cited negative behavioral behavioral changes in wildlife as the result of some ORV use[7].
Some U.S. states have laws to reduce noise pollution generated by off-road and non-highway vehicles. Washington State is one example: "State law requires off-road and other non-highway vehicles to use specified noise-muffling devices (RCW 46.09.120(1) (e) maximum limits and test procedures). State agencies and local governments may adopt regulations governing the operation of non-highway vehicles on property, streets, or highways within their jurisdiction, provided they are not less stringent than state law (RCW 46.09.180 regulation by local political subdivisions)"[8].
Roadless area conservation
Many U.S. National Parks have discussed or enacted roadless rules and partial or total bans on ORVs. To accommodate enthusiasts, some parks like Big Cypress National Preserve in Florida, were created specifically for ORVs and related purposes. However, such designations have not prevented damage or abuse of the policy[9] [10].
Public statements
In 2004, several environmental organizations sent a letter to Dale Bosworth, Chief of the United States Forest Service, and described the extent of damage caused by ORV use, including health threats to other people:
It is well-established that the proliferation of off-road vehicle and snowmobile use places soil, vegetation, air and water quality, and wildlife at risk through pollution, erosion, sedimentation of streams, habitat fragmentation and disturbance, and other adverse impacts to resources. These impacts cause severe and lasting damage to the natural environment on which human-powered and equestrian recreation depends and alter the remote and wild character of the backcountry. Motorized recreation monopolizes forest areas by denying other users the quiet, pristine, backcountry experience they seek. It also presents safety and health threats to other recreationists [11].
U.S. Supreme Court Justice Antonin Scalia, in a 2004 ruling considered a blow to environmentalists, listed several problems that result from ORV use in natural areas. From the Environmental News Service article:
"Scalia noted that off-road vehicle use on federal land has 'negative environmental consequences including soil disruption and compaction, harassment of animals, and annoyance of wilderness lovers.'"[12]