Countersteering is the technique used by single-track vehicle A vehicle is a device that is designed or used to transport people or cargo. Most often vehicles are manufactured (e.g. bicycles, cars, motorcycles, trains, ships, boats, and aircraft) operators, cyclists Cycling, also called bicycling or biking, is the use of bicycles for transport, recreation, or for sport. Persons engaged in cycling are cyclists. or bicyclists. Apart from ordinary two-wheeled bicycles, cycling also includes riding unicycles, tricycles, quadracycles, and other similar human-powered vehicles and motorcyclists Motorcycling is the act of riding a motorcycle. A variety of subcultures and lifestyles have been built up around motorcycling, to initiate a turn toward a given direction by first steering counter to the desired direction ("steer left to turn right"). To negotiate a turn successfully, the combined center of mass The center of mass of a system of particles is the point at which the system's whole mass can be considered to be concentrated for the purpose of calculations. The center of mass is a function only of the positions and masses of the particles that compose the system. In the case of a rigid body, the position of its center of mass is fixed in of the rider and the single-track vehicle A vehicle is a device that is designed or used to transport people or cargo. Most often vehicles are manufactured (e.g. bicycles, cars, motorcycles, trains, ships, boats, and aircraft) must first be leaned in the direction of the turn, and steering briefly in the opposite direction causes that lean. Once sufficient lean is established to sustain the desired turn, the rider, or in many cases the bike itself, then steers into the turn to cause the bike to turn in the desired direction and stop the lean from increasing. This technique does not apply to multiple-tracked vehicles such as trikes A tricycle is a three-wheeled vehicle. While tricycles are often associated with the small three-wheeled vehicles used by pre-school age children, they are also used by adults for a variety of purposes. In the United States and Canada, adult-sized tricycles are used primarily by older persons for recreation, shopping, and exercise. In Asia and and bicycles A bicycle, also known as a bike, pushbike or cycle, is a pedal-driven, human-powered, single-track vehicle, having two wheels attached to a frame, one behind the other. A person who rides a bicycle is called a cyclist or a bicyclist or motorcycles with sidecars A sidecar is a one-wheeled device attached to the side of a motorcycle, producing a three-wheeled vehicle. Early sidecars were intended to be removable devices that could be detached from the motorcycle. The first mention of a sidecar is in a cartoon by George Moore in the January 7, 1903 issue of the British newspaper "Motor Cycling" attached.
It is important to distinguish between countersteering as a physical phenomenon and countersteering as a rider technique for initiating a lean (the usual interpretation of the term). The physical phenomenon always occurs, because there is no other way to cause the bike and rider to lean short of some outside influence such as an opportune side wind, although at low speeds it can be lost or hidden in the minute corrections made to maintain balance.
At the same time, the rider technique of applying pressure to the handlebars Handlebars usually refer to the steering mechanism for bicycles, motorcycles, ATVs, snowmobiles and personal watercraft; the equivalent of a steering wheel. Besides acting as a steering mechanism, handlebars also may support a portion of the rider's weight, depending on his or her riding position to initiate a lean is not always necessary, since, on a sufficiently light bike (especially a bicycle A bicycle, also known as a bike, pushbike or cycle, is a pedal-driven, human-powered, single-track vehicle, having two wheels attached to a frame, one behind the other. A person who rides a bicycle is called a cyclist or a bicyclist), the rider can initiate a lean and turn by shifting body weight, called counter-lean by some authors.[1][2][3] Documented physical experimentation shows that on heavy bikes (many motorcycles A motorcycle is a single-track, two-wheeled motor vehicle. Motorcycles vary considerably depending on the task for which they are designed, such as long distance travel, navigating congested urban traffic, cruising, sport and racing, or off-road conditions) shifting body weight is less effective at initiating leans.[4]
It is also important to distinguish the steering torque and steering angle necessary to establish the lean required for a given turn from the sustained steering torque and steering angle necessary to maintain a constant radius and lean angle until it is time to exit the turn. The initial steer torque and angle are both opposite the desired turn direction. The sustained steer angle is in the same direction as the turn. The sustained steer torque required to maintain that steer angle is either with or opposite the turn direction depending on forward speed, bike geometry, and combined bike and rider mass distribution.
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Bikes vs automobiles
Automobiles steer by imposing a steer angle between the front and rear wheels. Broadly speaking, the response of the vehicle is related to that angle; the automobile is a "position-controlled" system in normal use.
Bikes steer by controlling roll angle. However roll angle is not directly manipulated by the handlebars in the same way as steer angle in an automobile. Rather it is influenced indirectly by applying roll moments to the machine. These roll moments in turn come from side forces at the wheels, which are closely related to steering torques. Thus the bike is a "force-controlled" system in which the actual position of the handlebars is free.[citation needed]
The lean of a bike's wheels causes a turning force in the direction of the lean, called camber thrust, which enables the bike to negotiate turns with substantially less steering angle of the front wheel than an automobile for the same turn radius.[3]
How it works
A single-track vehicle such as a bicycle or a motorcycle is an inverted pendulum An inverted pendulum is a pendulum which has its mass above its pivot point. It is often implemented with the pivot point mounted on a cart that can move horizontally and may be called a cart and pole. Whereas a normal pendulum is stable when hanging downwards, an inverted pendulum is inherently unstable, and must be actively balanced in order to—it will fall over unless balanced.
The technique used by cyclists Cycling, also called bicycling or biking, is the use of bicycles for transport, recreation, or for sport. Persons engaged in cycling are cyclists. or bicyclists. Apart from ordinary two-wheeled bicycles, cycling also includes riding unicycles, tricycles, quadracycles, and other similar human-powered vehicles and motorcyclists Motorcycling is the act of riding a motorcycle. A variety of subcultures and lifestyles have been built up around motorcycling to initiate turning in a given direction is to first apply a steering torque in the opposite direction. For example, if a turn to the left is desired, it is started by a turn of the handlebars to the right. Under this force the front wheel will rotate to turn right and the front tire will generate forces to the right. The machine as a whole steers to the right briefly and the rear tire also generates forces to the right. Because the forces are applied at ground level, this pulls the wheels "out from under" the motorcycle and to its right. The resulting roll angle to the left causes the tires to then generate camber thrust to the left providing the centripetal Centripetal force is a force that makes a body follow a curved path: it is always directed orthogonal to the velocity of the body, toward the instantaneous center of curvature of the path. The term centripetal force comes from the Latin words centrum and petere ("tend towards", "aim at"), signifying that the force is directed forces required to turn left. The geometry of the steering system provides the forces necessary for the front wheel to adopt an angle turned into the turn in a conventional manner.[5] It is often boiled down to "push left to go left".
While this appears to be a complex sequence of motions, it is in fact known unconsciously by every child who rides a bicycle. The entire sequence goes largely unnoticed by most riders, which is why some assert that they don't do it.
It is often claimed that two-wheeled vehicles can be steered using only weight shifts. While this is true for small "trim" inputs to direction, complex maneuvers are not possible using weightshifting alone because even for a light machine there is insufficient control authority.[6] Although on a sufficiently light bike (especially a bicycle A bicycle, also known as a bike, pushbike or cycle, is a pedal-driven, human-powered, single-track vehicle, having two wheels attached to a frame, one behind the other. A person who rides a bicycle is called a cyclist or a bicyclist), the rider can initiate a lean and turn by shifting body weight,[1] there is no evidence that complex maneuvers can be performed by bodyweight alone.[4]
It is also important to distinguish the steering torque necessary to initiate the lean required for a given turn from the sustained steering torque and steering angle necessary to maintain a constant radius and lean angle until it is time to exit the turn. The initial steer torque and angle are both opposite the desired turn direction. The sustained steer angle is in the same direction as the turn. The sustained steer torque required to maintain that steer angle is either with or opposite the turn direction depending on forward speed, bike geometry, and combined bike and rider mass distribution.
Countersteering is necessary to adjust the angle of lean of a bicycle and works in the opposite sense to the handlebar input while conventional steering in the direction of the turn is used in conjunction with camber thrust to negotiate the turn.
Need to lean to turn
A bike can negotiate a curve only when the combined center of mass The center of mass of a system of particles is the point at which the system's whole mass can be considered to be concentrated for the purpose of calculations. The center of mass is a function only of the positions and masses of the particles that compose the system. In the case of a rigid body, the position of its center of mass is fixed in of bike and rider leans toward the inside of the turn at an angle appropriate for the velocity and the radius of the turn:
where v is the forward speed, r is the radius of the turn and g is the acceleration of gravity Gravitation, or gravity, is one of the four fundamental interactions of nature , in which objects with mass attract one another. In everyday life, gravitation is most familiar as the agent that gives weight to objects with mass and causes them to fall to the ground when dropped. Gravitation causes dispersed matter to coalesce, thus accounting for.[1]
Higher speeds and tighter turns require greater lean angles. If the mass is not first leaned into the turn, the inertia Inertia is the resistance of any physical object to a change in its state of motion. It is represented numerically by an object's mass. The principle of inertia is one of the fundamental principles of classical physics which are used to describe the motion of matter and how it is affected by applied forces. Inertia comes from the Latin word, " of the rider and bike will cause them to continue in a straight line as the tires track out from under them along the curve. The transition of riding in a straight line to negotiating a turn is a process of leaning the bike into the turn, and the only way to cause that lean (of the combined center of mass of bike and rider) is to move the support points in the opposite direction first.[7] The rider can shift his weight of course, but any force used to move one way laterally pushes the bike laterally the opposite direction with equal force. That makes the bike lean (and can affect the steering), but it does not change the combined center of mass of bike and rider.
Lean by countersteering
When riding a bicycle or a motorcycle, countersteering is a method of initiating a turn by a small, momentary turn of the front wheel, usually via the handlebars, in the opposite (counter) direction. This moves the pivot point (the wheels' contact patches) out from under the center of mass to establish the lean angle for a turn. While necessary at all speeds, the need to countersteer becomes more noticeable as speed increases.
Hence, to turn to the right, the rider first throws the bike off balance by momentarily pointing the front wheel slightly to the left. The center of mass of the bike plus rider will continue in a straight line, but the contact patches of the tires move to the left with respect to this straight line.
Once lean is achieved
As the desired angle is approached, the front wheel must then be steered into the turn to maintain that angle or the bike will continue to lean with gravity, increasing in rate, until the side contacts the ground. This process usually requires little physical effort, because the geometry of the steering system of most bikes Bicycle and motorcycle geometry is the collection of key measurements that define a particular bike configuration. Primary among these are wheelbase, steering axis angle, fork offset, and trail. These parameters have a major influence on how a bike handles is designed in such a way that the front wheel has a strong tendency to steer in the direction of a lean.
The actual torque the rider must apply to the handlebars to maintain a steady-state turn is a complex function of bike geometry, mass distribution, rider position, turn radius, and forward speed. At low speeds, the steering torque necessary from the rider is usually negative, that is opposite the direction of the turn, even when the steering angle is in the direction of the turn. At higher speeds, the direction of the necessary input torque often becomes positive, that is in the same direction as the turn.[8]
Adjusting or exiting a turn
Once in a turn, countersteering is again required to make changes to its shape. The only way to decrease the radius at the same speed is to increase the lean angle, and the only way to increase the lean angle, is again to momentarily steer opposite to the direction of the curve. To the untrained, this can be extremely counter-intuitive.
To exit a turn, countersteer by momentarily steering further in the direction of the turn. This tilts the bike back upright.
At low speeds
At low speeds countersteering is equally necessary, but the countersteering is then so subtle that it is hidden by the continuous corrections that are made in balancing the bike, often falling below a just noticeable difference In psychophysics, a just noticeable difference, customarily abbreviated with lowercase letters as jnd, is the smallest detectable difference between a starting and secondary level of a particular sensory stimulus. It is also known as the difference limen or the differential threshold or threshold of perception of the rider. Countersteering at low speed may be further concealed by the ensuing much larger steering angle possible in the direction of the turn.
Unconscious behavior
Countersteering is indispensable for bike steering. Most people are not consciously aware that they employ countersteering when riding their bike any more than they are aware of the physics of walking. They have learned to subconsciously apply the required countersteering.
As is well-known in bicycle racing Bicycle racing is a sport encompassing many forms in which bicycles are used for competition. This racing includes road bicycle racing, cyclo-cross, mountain bike racing, track cycling, BMX and bike trials and cycle speedway, the countersteering phenomenon becomes evident when there is an obstacle preventing the wheel from countersteering (e.g., when closely overlapping wheels or riding very close to a curb). In these situations, the only way to initiate a turn away from the obstacle is to come into contact with it, that is, countersteer towards the wheel or curb to avoid crashing into it.[7] Lack of understanding of this principle leads to accidents in novice bicycle races.
Gyroscopic effects
One effect of turning the front wheel is a roll moment caused by gyroscopic precession Precession is a change in the orientation of the rotation axis of a rotating body. It can be defined as a change in direction of the rotation axis in which the second Euler angle is constant. In physics, there are two types of precession: torque-free and torque-induced. The magnitude of this moment is proportional to the moment of inertia Moment of inertia, also called mass moment of inertia, rotational inertia, or the angular mass, is a measure of an object's resistance to changes in its rotation rate. It is the rotational analog of mass, the inertia of a rigid rotating body with respect to its rotation. The moment of inertia plays much the same role in rotational dynamics as mass of the front wheel, its spin rate (forward motion), the rate that the rider turns the front wheel by applying a torque to the handlebars, and the cosine In mathematics, the trigonometric functions are functions of an angle. They are used to relate the angles of a triangle to the lengths of the sides of a triangle. Trigonometric functions are important in the study of triangles and modeling periodic phenomena, among many other applications of the angle between the steering axis and the vertical.[8]
For a sample motorcycle moving at 22 m/s (50 mph) that has a front wheel with a moment of inertia of 0.6 kgm2, turning the front wheel one degree in half a second generates a roll moment of 3.5 Nm. In comparison, the lateral force on the front tire as it tracks out from under the motorcycle reaches a maximum of 50 N. This, acting on the 0.6 m (2 ft) height of the center of mass, generates a roll moment of 30 Nm.[8]
While the moment from gyroscopic forces is only 12% of this, it can play a significant part because it begins to act as soon as the rider applies the torque, instead of building up more slowly as the wheel out-tracks. This can be especially helpful in motorcycle racing Motorcycle racing (also known as moto racing and bike racing (common term)) is a motorcycle sport involving racing motorcycles.[8]
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Jackson Sun, TN
Topics include advanced maneuvers, skid control, counter-steering and the management of complex situations. Co-riders will learn their role and function. Participants are required to furnish their own registered and insured motorcycle and a ...
