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Awheelie, orwheelstand,[1] is a vehicle maneuver in vehicleacrobatics in which the front wheel or wheels come off the ground due to sufficient torque being applied to the rear wheel or wheels,[2] or rider motion relative to the vehicle. Wheelies are usually associated with bicycles and motorcycles, but can be done with other vehicles such as cars, especially indrag racing andtractor pulling.
The first wheelie was reportedly performed by trick bicyclist Daniel J. Canary in 1890, shortly after modern bicycles became popular.[3][4][5] Writing in 2009,Mike Seate related to the U.S. Army motorizedcavalry training in 1943, pictured in Life magazine. Seate described "vaulting trenches and beach obstacles" and interpreted this technique as "High speed wheelies, naturally".[6] DaredevilEvel Knievel performed motorcycle acrobatics including wheelies in his shows. Doug "The Wheelie King" Domokos has accomplished such feats as a 145-mile (233 km) wheelie.[7]
Types of wheelie can be divided into two broad categories:
Wheelies are a common stunt infreestyle fixed gear,artistic cycling andfreestyle BMX. The bicycle is balanced by the rider's weight and sometimes use of the rear brake. A style of bicycle, thewheelie bike, has a seating position, and thuscenter of mass, nearly over the rear wheel that facilitates performing wheelies.
A wheelie is also a commonmotorcycle stunt. The principles is the same as the bicycle wheelie, but the throttle and rear brakes are used to control the wheelie while a rider uses body weight and the steering to control the direction the inertia of the spinning front wheel acting as a balance.[8]
The world's fastest motorcycle wheelie record is 307.86 km/h (191.30 mph) byPatrik Fürstenhoff. April 18, 1999.[9]The world record for the fast wheelie over 1 km (0.6 mi) is 343.388 km/h (213.371 mph),[10] set byEgbert van Popta atElvington airfield inYorkshire, England.[11]
In some countries, such as the United Kingdom and USA,[12] motorcyclists performing a wheelie on apublic road may be prosecuted fordangerous driving,[13][14] an offense which can carry a large fine and a ban of a year or more.[15]
In Pakistan, India, and some other countries, it is illegal to perform these kinds of stunts. If someone is caught performing these acts, the rider can have their motorcycle impounded and potentially face jail time.[16]
Wheelies are common inauto- ormotorcycle drag racing, where they representtorque wasted lifting the front end, rather than moving the vehicle forward. They also usually result in raising the center of mass, which limits the maximum acceleration. In the absence of wheelie bars, this effect is quantified in the physics section below. If wheelie bars are present then a wheelie results in a reduction of load on the rear driving wheels, along with a corresponding reduction infriction.
Monster trucks often perform wheelies during shows. Monster trucks have performed power wheelies, slap wheelies, and sky wheelies. To perform a sky wheelie, a monster truck jumps in such a way that the truck is vertical in the air, with the front end of the truck pointing upwards.
Wheelies are possible with somesnowmobiles, whereby it is the skis that are lifted off the ground.
Somewheelchair users can learn to balance their chair on its rear wheels and do a wheelie. This enables them to climb and descend curbs and maneuver over small obstacles.[17] Occasionallywheelchair dancers perform wheelies.
In an airplane, a wheelie is performed by conducting a soft-field landing or take-off procedure. The pilot increases the elevator backpressure so the nose wheel of the landing gear has minimal contact with the ground.
On 14 February 2020, theGuinness World Record for the longest-distance wheelie in an airplane was set in aCessna 172 atSouthern California Logistics Airport inVictorville, California on runway 17. The pilot kept the plane's nose wheel from touching the runway for a distance of 14,319 feet.[18][19][20]
Awheelie bar helps prevent a vehicle's front end from raising too high or flipping over. A bar is required for some tractor and truck pull events.[21][22]Wham-O developed and sold an add-on wheelie bar forwheelie bikes.
A wheelie is imminent when the acceleration is sufficient to reduce the load borne by the front axle to zero.[23] The conditions for this can be calculated with the so-called "weight transfer equation":
where is the change in load borne by the front wheels, is the longitudinal acceleration, is the center of mass height, is the wheelbase, and is the total vehicle mass.[24][25]
An equivalent expression, which does not require knowing the load borne by the front wheels nor the total vehicle mass, is for the minimum longitudinal acceleration required for a wheelie:
where is theacceleration due to gravity, is the horizontal distance from the rear axle to the center of mass, and is the vertical distance from the ground to the center of mass.[26] Thus the minimum acceleration required is directly proportional to how far forward the center of mass is located and inversely proportional to how high it is located.
Sincemechanical power can be defined as force times velocity, in one dimension, andforce is equivalent to mass times acceleration, then the minimum power required for a wheelie can be expressed as the product of mass, velocity, and the minimum acceleration required for a wheelie:
Thus the minimum power required is directly proportional to the mass of the vehicle and to its velocity. The slower a vehicle is moving, the less power is required to perform a wheelie, and that is without even considering the power required to overcomeair drag, which increases with the cube of velocity. Therefore, the least amount of power required is when the vehicle begins accelerating from rest.
In the case of tractor and truck pulling, the force to the pull the load is applied above the ground, and so it also acts to lift the front wheels and thus reduces the forward acceleration necessary to lift the front wheels.
The total power required during a wheel, neglecting air drag can be shown to be:
where is vehicle with mass, is the vehicleradius of gyration, and are distance from rear wheel contact patch to center of mass, is horizontal acceleration, is horizontal velocity, is angle of vehicle from horizontal, is angular velocity of vehicle rotation, and is angular acceleration of vehicle rotation. This can be separated into components necessary only for horizontal acceleration
and components necessary only for raising and rotating the vehicle
A factorM can be calculated as the ratio of the power required to raise and rotate the vehicle and the power required only for horizontal acceleration.[27]
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: CS1 maint: multiple names: authors list (link)Wheelie bars are required in Divisions II, IIT, III, IV & V
All 2wd trucks are required to have wheelie bars on them