Truggies, buggies and juggies are not usually found in civilized parts of the world, but several of the custom-built off-road trucks are expected to overrun Charlotte Motor Speedway during the Aug. 25-28 Food Lion AutoFair. These extreme-performance four-wheeled beasts will be joined in the Showcase Garage by an exhibit offering 100 years of Chevrolet automobiles, the world's lowest street-legal car, armored passenger vehicles and cars from movies and television. Two Charlotte-area shops are bringing more than a dozen rock crawlers for the display. Matthews, N.C.-based Carolina Truggies has a reputation for building "the sickest rigs on the East Coast" since Alex Reed transformed his hobby/obsession into a business in 2006. Chris Marshall, of MarsFab Off Road in Harrisburg, N.C., was a well-known welder and fabricator for the four-wheel-drive community before he began specializing in turnkey machines. Each looks forward to introducing the Food Lion AutoFair crowd to this growing form of extreme recreation. "Rock crawler" is the generic term for any rig built to travel the type of boulder-strewn paths that would damage or destroy ordinary pickups or SUVs. The smallest rocks encountered might be the size of melons; the biggest – kitchen refrigerators. The wide variety of terrain encountered on a trail means there are many types of crawlers, depending on an owner's experience level and budget. A novice trail enthusiast might modify a four-wheel-drive pickup by adding heavy-duty off-road suspension parts, chopping off the body's rear overhang and bolting in a rollcage. An expert builder will marry a race car-like tube-frame chassis to a very tall coil-over-shock suspension system and chest-high tires. Tube-frame crawlers wearing a few pieces of flat sheet metal for driver protection are known as "buggies," and they resemble Baja-style dune buggies. When fitted with a recognizable truck body, a buggy becomes a "truggy;" if it looks like a Jeep Wrangler or other Jeep product, it is a "juggy." Snow, ice, water and slabs of granite do not deter the best crawler drivers from reaching their destinations, but speed is not a priority in this motorsport. Climbing over large obstacles takes a lot of power and that means low gears that multiply the engine's torque but severely limit top speed. Tires range in diameter from 33 to 52 inches. Many drivers prefer automatic transmissions because it is easier to balance the brake and throttle when only two pedals are involved. Axle gears and shafts are the first victims of a rough trail, so builders tend to replace them with super-heavy-duty parts from 2.5-ton military trucks. Rock crawlers engineered for severe conditions feature four-link suspensions and coil-over shock absorbers that allow the axles to dip and rise as much as 36 inches. This articulation of the major suspension components makes it possible for a crawler to cross uneven ground without rolling over. As a form of recreation, rock crawling is often associated with the wide-open spaces of the Rocky Mountains, but there is a community of enthusiasts enjoying the Carolinas' trails year-round. The 51,000-acre Uwharrie National Forest an hour east of Charlotte, N.C., is a popular place to ride, with 13 miles of trails open to the public from April through December. For socializing, hardcore off-roaders don't miss the annual Big Dixie Boggers Fall Rock Harvest at the Rock Farm in Lincolnton, N.C. – a three-day family event featuring camping, live music, games and, of course, rock crawling. Food Lion AutoFair Hours for the Aug. 25-28 Food Lion AutoFair are 8 a.m. to 6 p.m., Thursday through Saturday, and 8 a.m. to 4 p.m., Sunday. Ticket prices are $10 per day for adults or $25 for a four-day pass; children under 12 are admitted free when accompanied by an adult. Parking for the event is $5. For more information on the four-day event, contact the speedway events department at (704) 455-3205 or visit www.charlottemotorspeedway.com.