Off-road tires (Off-road tyre) are a category of vehicle tires that use deep tread to provide more traction on unpaved surfaces such as loose dirt, mud, sand, or gravel. [1] Compared to ice or snow tires, they lack studs but contain deeper and wider grooves meant to help the tread sink into mud or gravel surfaces.
Off-road tires are typically radials [2] with thick, deep tread. On dirt surfaces, the exposed edges of the tread dig into soft ground to give more traction than rolling friction alone, analogous to the traction provided by cleated shoes. These off-road tires provide their maximum grip on loose surfaces, but on paved surfaces the smaller contact patch affords less traction as compared to street tires. Tires with less aggressive knobs (smaller knobs and the shape of the tread cross-section closer to that of street tires) can provide a compromise, giving less grip off-road, but a grip closer to that of street tires on paved surfaces. Such tires are useful for enduro and dual-sport motorcycles and other vehicles designed to be used both off-road and on pavement.
Some off-road tires are designed to be used with low inflation pressure on difficult terrain, reducing their rigidity and allowing the tread to better conform to the terrain. [3] Such a design may allow for use on a wider range of surfaces, but tubeless tires running under rated pressure run the risk of breaking their bead. A beadlock can be used to prevent this.
Off-road cycle tires, colloquially called knobbies, [4] may be found on motocross and enduro motorcycles, ATVs, and mountain bikes. [1] Tires for single-track vehicles and ATVs have a curved profile such that some tread only contacts the ground during turning.
Depending on the model of tire, an off-road capable tire may or may not be approved by the DOT. [5] In the United States, such a tire approved for street use will be marked with a DOT code (U.S.), which identifies the tire as street legal. Tires which are not approved for street use will typically be labeled "Motocross Use Only" or "Not for Highway Use". Street legal, knobby tires are generally not suitable for long distances on roads or paved surfaces because of poor NVH properties and excessive wear on the soft rubber.
Depending on the design, an off-road tire may be designated "all terrain" ("All-around"), meaning it is intended for use both on- and off-road. Such tires attempt to compromise between grip on loose terrain and safety or comfort on paved roads. Some tires, such as the bar grip used on United States military vehicles in World War II, accomplish this by separating the tire into distinct on-road and off-road tread zones. Modern all-terrain tires typically employ hybrid tread patterns and tougher compound to increase the wear life under mixed-surface conditions. [6]
All-terrain tires are known for their ability to handle different terrains. They come with grooves and channels that distribute the load evenly, improving the traction. This makes all-terrain tires ideal for off-road driving, snow and ice, sand, and other soft surfaces. They are also known for their long lasting performance.
Some of the key features of all-terrain tires (ATTs). [7]
A tire or tyre is a ring-shaped component that surrounds a wheel's rim to transfer a vehicle's load from the axle through the wheel to the ground and to provide traction on the surface over which the wheel travels. Most tires, such as those for automobiles and bicycles, are pneumatically inflated structures, providing a flexible cushion that absorbs shock as the tire rolls over rough features on the surface. Tires provide a footprint, called a contact patch, designed to match the vehicle's weight and the bearing on the surface that it rolls over by exerting a pressure that will avoid deforming the surface.
A mountain bike (MTB) or mountain bicycle is a bicycle designed for off-road cycling. Mountain bikes share some similarities with other bicycles, but incorporate features designed to enhance durability and performance in rough terrain, which often makes them heavier, more complex and less efficient on smooth surfaces. These typically include a suspension fork, large knobby tires, more durable wheels, more powerful brakes, straight, extra wide handlebars to improve balance and comfort over rough terrain, and wide-ratio gearing optimised for topography, application and a frame with a suspension mechanism for the rear wheel. Rear suspension is ubiquitous in heavier-duty bikes and now common even in lighter bikes. Dropper seat posts can be installed to allow the rider to quickly adjust the seat height.
Motocross is a form of off-road motorcycle racing held on enclosed off-road circuits. The sport evolved from motorcycle trials competitions held in the United Kingdom.
Off-road transport is moving people or articles on land without the use of paved roads, typically using off-road vehicles.
A racing slick or slick tyre is a type of tyre that has a smooth tread used mostly in auto racing. The first production slick tyre was developed by M&H Tires in the early 1950s for use in drag racing. By eliminating any grooves cut into the tread, such tyres provide the largest possible contact patch to the road, and maximize dry traction for any given tyre dimension. Slick tyres are used on race tracks and in road racing, where acceleration, steering and braking require maximum traction from each wheel. Slick tyres are typically used on only the driven (powered) wheels in drag racing, where the only concern is maximum traction to put power to the ground, and are not used in rallying.
An off-road vehicle (ORV), sometimes referred to as an off-highway vehicle (OHV), overland vehicle, or adventure vehicle, is considered to be any type of vehicle that is capable of driving off road on non-paved surfaces, such as trails and forest roads that have rough and low-traction surfaces.
Cyclo-cross is a form of bicycle racing. Races typically take place in the autumn and winter, and consist of many laps of a short course featuring pavement, wooded trails, grass, steep hills and obstacles requiring the rider to quickly dismount, carry the bike while navigating the obstruction and remount. Races for senior categories are generally between 40 minutes and an hour long, with the distance varying depending on the ground conditions. The sport is strongest in the traditional road cycling countries such as Belgium, France and the Netherlands.
A cyclo-cross bike or cyclo-cross bicycle is a bicycle specifically designed for the rigors of a cyclo-cross race. Cyclo-cross bicycles roughly resemble the racing bicycles used in road racing. The major differences between the two are the frame geometry, and the wider clearances that cyclo-cross bikes have for their larger tires and mud and other debris that they accumulate.
The tread of a tire or track refers to the rubber on its circumference that makes contact with the road or the ground. As tires are used, the tread is worn off, limiting its effectiveness in providing traction. A worn tire can often be retreaded.
Paddle tires are mainly used on off-road vehicles, specifically designed for use in sand and mud. They consist of a smooth tire core which has a series of large rubber cups attached to it. The volume inside of a paddle is much larger than the void of a knobby tire, so it is unlikely to clog up with sand/mud. A street legal mud tire is a more or less normal tire, but with extra large gaps or "voids" between each tread block to allow centrifugal force to "self-clean" or fling the mud out of the gap. Smaller gaps trap the mud in between the tire lugs, which turns the tire into something resembling a "slick" with no tread at all, which will have no traction in mud.
Ice racing is a form of racing that uses cars, motorcycles, snowmobiles, all-terrain vehicles, or other motorized vehicles. Ice racing takes place on frozen lakes or rivers, or on groomed frozen lots. As cold weather is a requirement for natural ice, it is usually found at higher latitudes in Canada, the northern United States, and in northern Europe, although limited indoor events are held in warmer climates, typically on ice hockey rinks. Tracks in North America vary from 1/4 mile to several mile-long circuits.
In the market, there is a wide variety of types of motorcycles, each with unique characteristics and features. Models vary according to the specific needs of each user, such as standard, cruiser, touring, sports, off-road, dual-purpose, scooters, etc. Often, some types like sport touring are considered as an additional category or integrated with touring.
A dual-sport motorcycle is a type of motorcycle that is designed for varying degrees of off-road use while still being street-legal. Dual-sports may be equipped with lights, a speedometer, mirrors, a horn, registration plates, and a muffler to comply with local regulations. Other names such as all-road, on/off-road, dual-purpose, and adventure bike may be chosen by the manufacturer based upon the size, weight, and intended application of the motorcycle.
The motorcycle sport of racing includes motorcycle road racing and off-road racing, both either on circuits or open courses, and track racing. Other categories include hill climbs, drag racing and land speed record trials.
Motorcycle components and systems for a motorcycle are engineered, manufactured, and assembled in order to produce motorcycle models with the desired performance, aesthetics, and cost. The key components of modern motorcycles are presented below.
A bicycle tire is a tire that fits on the wheel of a bicycle or similar vehicle. These tires may also be used on tricycles, wheelchairs, and handcycles, frequently for racing. Bicycle tires provide an important source of suspension, generate the lateral forces necessary for balancing and turning, and generate the longitudinal forces necessary for propulsion and braking. Although the use of a pneumatic tire greatly reduces rolling resistance compared to the use of a rigid wheel or solid tire, the tires are still typically the second largest source, after wind resistance, of power consumption on a level road. The modern detachable pneumatic bicycle tire contributed to the popularity and eventual dominance of the safety bicycle.
A motorcycle tyre is the outer part of motorcycle wheel, attached to the rim, providing traction, resisting wear, absorbing surface irregularities, and allowing the motorcycle to turn via countersteering. The two tyres' contact patches are the motorcycle's connection to the ground, and so are fundamental to the motorcycle's suspension behaviour, and critically affect safety, braking, fuel economy, noise, and rider comfort.
A BMX bike is a bicycle used for road cycle sport, specifically racing or stunt riding. BMX stands for bicycle motocross.
The following outline is provided as an overview of and topical guide to tires:
Bar grip tyres, or 'NDT' in US military parlance, are an early tyre tread pattern developed for off-road use.
