Piloting (motor bike)

The piloting of a machine with two wheels is governed by precise physical rules important to know for safety, the performance and the pleasure of control.

General information

The reversed steering

At the speeds lower than 20 km/h, stability is easily obtained by a constant adjustment carried out by the pilot thanks to the handlebar, in the same way that with a Bicyclette. The direction of the motor bike is then controlled by the handlebar and the position of the motorcyclist; to turn the handlebar on the right (to push its left branch) will drive the motor bike towards the line, and conversely.

With high speeds with 20 km/h, the position of the motorcyclist has little importance in the direction taken, the opposite steering constitutes the only effective method of change of management of emergency avoidance of obstacles. This phenomenon being rather contrary so that the beginner motorcylcist thinks, the motor bike-schools state simply that " is needed; to push the handlebar on the side where tourner" is wanted; to give a pretense of logic to the operation.

The reversed steering, badly properly indicated like a steering into the skid, is the exploitation of a physical law. When the motor bike goes more quickly, the stability is ensured by the combined action of hunting (geometry of direction) and the gyroscopic effect of the wheels which is opposed to the slope of the motor bike. Although many motor bike-schools explain why the phenomenon is with the gyroscopic Précession, the explanation of the opposite steering is the following one: at high speed, the motor bike has an important inertia ( $E= \ frac {m.v^2} 2$ ). When one turns the handlebar of with dimensions (for example on the left), the contact point wheel-ground moves in the corresponding direction (on the left). However, because of the important inertia of the machine, the center of gravity continues to follow a rectilinear trajectory. So the motor bike leans in the direction opposed to steering (IE: on the right). Once leaning, it turns naturally in this direction, contrary thus to the impulse given to the handlebar; it is the car-steering.

The gyroscopic Precession of the wheel contrinue also to time against-direction and guidance while leaning. The slope of the wheels compared to the ground, named set, involves guidance. The more the wheels are inclined, the more the motor bike turns (thus we make turn a wheelbarrow to a wheel, by inclining it). The wheel reacts to the force which is applied to him while turning to 90 degrees of this one. Other big factors influence the direction of the motor bike, as the geometry of the framework, in particular the slope of the fork compared to the direct wheel axle (the nose gear wheel). The proof is the fact that one can keep stability without the assistance of the hands, and, to a certain extent, to move, as well as the fact that one can keep stability and to move on only one wheel (a Stoppie for the aft wheel raised and a wheeling for the nose gear wheel lifting).

Piloting on the road field

The position of control

The catch of turn is facilitated by a good position taking into account these points:

the pilot sat against the tank (the center of gravity is forwards);
the knees tighten the tank (better stability);
the feet are not out of duck and their broad part is posed on their rest-foot;
the arms are in alignment wrist-elbow-shoulders, i.e. the elbows are not isolated;
the back right but is not slightly stretched behind to lighten the wrists and to still bring closer the center of gravity forwards;
the glance even goes on the point of cord on the exit of curve; a turn plugs or a control of night prevents this glance and consequently the anticipation of piloting.

Contrary to piloting on track, the Déhanché does not bring more performance; it results an additional taking risk from it. Indeed, this position verouille the direction of the motor bike and obliges to take the cord of the turn before having a sufficient visibility to pass in full safety; no emergency movement is realizable properly under these conditions. On the contrary, the pilot remains flexible and more right which the motor bike what makes it possible to make quickly counterweight in the event of immediate danger. Moreover, the cord of the turn is to be taken only when the visibility allows it, i.e. later that in déhanché. The fact of being flexible all while maintaining the motor bike by the knees allows a fast action and an early exit of turn.

Trajectories

The force Centrifuge had with the Inertie of the vehicle naturally imposes a rectilinear trajectory and a force towards the outside of the turn; it depends on the mass, the speed and the ray of the turn ( $F= \ frac {M.v^2} R$ ). Only the force of adherence makes it possible the vehicle to follow a circular trajectory. In a natural way, the reflex is to look a few meters in front of its nose gear wheel with the manner of a child on his bicycle. It is fundamental to succeed in further exceeding these bad habits while looking at possible constantly, where the motor bike must pass. It is necessary to overcome this reflex, it is the key of anticipation, balance and finally of the pleasure with motor bike; that induces a shift between the glance, which anticipates, and the action in progress for which all is already decided. This way of acting brings a facility and a considerable safety.

Then, for safety reason, it is necessary to force with not to bite on the way being useful within the meaning of circulation opposed, not only the wheels but also the body; often the top of the body is found in the other way when the motor bike is tilted at the time of a passage in curve. A good means is to imagine and to be convinced that the other way does not exist; all must hold in the way usable.

Four stages

The trajectories on open road are different from those taken on a circuit for the simple one and good reason that to take the cord as soon as possible is not compatible with the need for visibility on the highway network. They can be isolated in four stages:

the position of entry : still in straight line, a turn is profiled with far. The analysis of the turn makes it possible to adapt the pace of the motor bike. Anticipation is maximum especially if braking only consists in applying only the driving brake;
the discovery of the turn : the turn arrives also it is necessary to be placed about the middle of the roadway for a turn on the right or on the right of the roadway for a turn on the left while waiting to have a total visibility on the unit of the turn; the glance goes possible further to research from possible obstacles;
the request : as soon as the exit of the turn is visible, it is the moment to act while against-directing in order to join the point of cord of the turn. It is necessary to take care not to cut the way;
the resumption of stability : if the way is free, a controlled D-acceleration makes it possible to rectify the motor bike to leave the turn.

Zones of danger

On the highway network, it is important to take into account the existence of danger zones as described on the diagram opposite. Certain turns are known as blind because they do not make it possible to have a sufficient visibility to see their end, it is the case in mountainous territory or when constructions mask the vision; a bad evaluation of the turn or a variable roadway of adherence is likely to surprise the pilot. In the event of turn on the right, it is necessary to take care not to run up against side obstacles (posts, slides, panels) because of the slope. The turns are to be taken preferably with pace reduced for then leaving easily with acceleration. He is vital of knowing which place occupies the motor bike on the road when it is tilted; this lapse of memory obliges the pilot to rectify and accentuate the steering into the skid to finish the turn when a vehicle is presented in opposite direction; the same problem emerges when the other vehicles cut the turn.

Use of braking

Active braking

Braking is one of the essential operations in the motor bike. It involves a deceleration producing a horizontal force directed of the back towards before following the principle of Inertie; the moment of this force compared to the axis of the wheels involves a downward vertical action on before translated by the depression of the fork, and an ascending vertical action relieving the aft wheel. Thus the Poids is distributed between before and the back in proportion to the distances from the wheels compared to the center of gravity of the motor bike unit and pilot. The direction of the weight is vertical and the direction of the effort of inertia is horizontal, also the distribution of the weight is superimposed on the effects of inertia of deceleration. This action is popularized in an incorrect way in term of transfer of mass.

The Suspension of vehicle S front make it possible, while being inserted, to absorb part of this additional weight. A braking before too supported under these conditions can involve the takeoff of the aft wheel (when the front suspensions arrive into obstinate) and/or blocking with skid of the nose gear wheel (it is the fall almost ensured in the latter case).

The front brake is most effective and can ensure 100% of braking. However, the back brake makes it possible to sit and to stabilize the machine, it also allows a late braking in curve. The pilot must apply the maximum of braking to the nose gear wheel by tightening the order gradually in order to obtain the mass transfer, therefore of adherence, on the nose gear wheel, while applying the back brake to balance the machine. The aft wheel, which is still in charge at the beginning of braking, can be braked fairly with non-braked when almost all the mass passed on the nose gear wheel. Proportioning brake before/back depends on the characteristics of the motor bike and of the tires, generally the proportion 70% with before and 30% with the back are recommended, back braking making it possible to stabilize the motor bike. A too important pressure on the back brake can involve the back wheel locking, which is however less critical than that of the nose gear wheel. It is enough for the pilot to slacken a little the pressure on the back brake to restore the good conditions and to finish its braking correctly.

During braking, the pilot must hold his knees tightened against the tank, the back more the right possible, the glance which carries high, right in front of and the arms are locked. The motor bike is if possible with the vertical, because the braking of the nose gear wheel causes to rectify the motor bike. At the time of the passage of the tests of the driving license, the candidates systematically receive an instruction on emergency braking. At the time of the passage of the technical part of the driving license, the candidate can have to carry out an emergency braking in front of the Inspecteur of the driving license.

Following the example cars, certain motor bikes, mainly with big-engined car are now equipped with anti-locking with the brakes known as ABS making it possible to limit the risks of blocking of wheel in the event of supported braking. There exists also a computer-assisted management of the proportioning of power between the nose gear wheels and back, such the dualone of the mark Honda or integral braking BMW.

The brake-engine

Each motorcyclist, according to his experiment, of his machine, of the atmospheric conditions, has for a turn given an ideal throughput speed to which it will feel safe. A good manners “to apprehend” this turn, “to read it”, to know the making safe throughput speed, consists in retrogressing sufficiently a long time in advance. That allows:

to have time to observe the approach of the turn, to integrate all the parameters, to anticipate;
to adjust the speed in a nonbrutal way;
to be rather in on-mode (preferable for, of a thread of gas, to have a constant speed in the turn);
not to have with concentrating too much on braking while having anticipated it. To be upright on the brakes at the entry of the turn causes a loss of concentration for the passage of the turn.

If the pilot feels an impression excessive speed, it is enough to give up the thread of gas to the profit of the driving brake which, combined with the increase in frictions in the turn, will make very quickly fall the speed which will be making safe very little time after the beginning of the turn. Generally, one will realize whereas indeed, one could have passed at the speed of entry.

Anticipation

More than any other characteristic of piloting, anticipation is the key of a good piloting. On circuit, that is summarized with a good sequence of accelerations, brakings and catches of angle. However, control on the highway network obliges to take into account other requirements:

insertion in the traffic: the advantage of a strong acceleration does not prevent from being surprised by a brutal braking of the vehicles fitting in front of the motor bike, or by a driver eager in the case of to pass at all costs before the motor bike an increase of file;
goings beyond: even fast, they must be judged correctly. The vehicles to be doubled can not leave enough place for an emergency folding back. A vehicle can suddenly decide to cut the axis to turn left, which often arrives to urban area and summer period. Certain paintings on the ground slipping and, are coupled with a thickness, destabilizing, becoming with a wet weather an accident risk;
the loophole: it is permanently necessary to envisage an emergency avoidance and by consequence the place which it will occupy (opening of doors, Pothole). Circulation on the fast track of left implies to deviate as well as possible from the vehicles of the adjacent way.
to be considering: the motorcyclist always rolls with the lit headlights dipped, obligatory even of day in the majority of the countries, in order to be more easily visible in the middle of the road traffic. The follow-up of a vehicle is done preferably on the left part of the way used what makes it possible to be better seen while being shown in the rear view mirrors exchange and left of the car. That offers moreover one loophole in the event of strong deceleration.

Displacements in group

It is often about a moment of pleasure and division of experiment. The motor bikes are generally of the same gauges in order to avoid frustrations of those which are with the block permanently and others which spend their time slowing down to await their congeneric.

There exist some particular rules that accustomed adopt within a group, but much are common to all the groups for safety reasons:

the ideal group does not pass 5 motor bikes;
the team leader, or guide , opens the way, it is tested the most and with a healthy behavior on the road and consequently it is often about oldest;
less tested follows the team leader to observe an good example;
most excited will be channeled while being placed behind the second;
the group is closed by somebody of as tested as the leader; he must make sure that all is well and must be able to go up to the team leader in the event of urgency, he is the " fire rouge" group, it makes sure that no danger will come from the back by a driver too in a hurry for example;
each one in its place, it is not a question to go up the maximum of buddies for the pleasure of passing in front;
displacement in straight line is carried out in quincunx: one on the left, the other further on the right, etc, in order to allow each one to have a sufficient visibility of the road and not to hang the predecessor during brakings not envisaged;
to avoid the effect of horde by not imposing to the other users additional constraints, for example at the time of the goings beyond or the parkings.

The goings beyond must be carried out with order by replacing its predecessor when this one continues his going beyond, it is not a question to be encrusted in mass between two vehicles.

Piloting on track

Some slightly prefer to deflate the tires to enable them to heat more quickly. If it is about a motor bike used also on the highway network, the suspensions must be hardened in order to limit the variations of attitude of the motor bike to accelerations and decelerations. It does not matter what it occurs behind, the trajectories must be easily anticipated by the others and the decelerations in straight lines announced while raising the left arm; that will avoid telescopings. In addition to the usual protection measures, a combination with Slider S is recommended for a better protection. It is advisable to check the validity of its insurance if this one is not included/understood in the price of hiring of the circuit.

The position of control

Displacements on the motor bike and the setting on the angle use the footrests, they have thus more importance than during control on road. The position Déhanché E is essential for four reasons:

that makes it possible to throw the motor bike on the angle by amplifying the effect of the steering into the skid
to move the body inside the turn makes it possible to remove angle with the motor bike, thus at speed equalizes a turn could be taken with less angle
the fact of posing the knee makes it possible to have a reference mark of angle
at the time of small slip of the aft wheel the fact of being " posé" on the knee allows the motor bike not to lie down

Contrary to control on road, to stick the body to the tank prevents mobility in the sequences; a few centimetres between the tank and controls it are welcome. It is the same for the knees: the pilot can loosen the pressure with the tank.

Trajectories

With the difference of control on road, all the width of the track must be used. The catch of trajectory can thus summarize with three great stages:

in straight line: braking, rétrogradage, glance with the cord;
entered of turn: steering into the skid, passage at the point of cord;
left the turn: to rectify the motor bike, to accelerate.

In a sequence of turns, it is necessary to privilege the last in order to leave as soon as possible. Generally, braking must take a minimum of time.

Use of braking

Braking is carried out the arms tended while being jettant behind in order to partly compensate for the mass transfer forwards which takes place during braking. It is useful to take reference marks to decrease the braking distances. Only two fingers placed on the handbrake lever make it possible to keep the other fingers on the throttle hand grip in order to be able to continue to exploit acceleration.

The back brake is applied little because of the important mass transfer during supported brakings. Its use is confined to sit the motor bike in entry of turn. In the less ideal case where the pilot enters a turn too quickly, the back brake makes it possible to slow down without brutally leaving the trajectory, thing inevitable with the braking of before only.

Piloting in any ground

Basic techniques

The turns generally occur shortest possible while rolling to pace reduced while playing with the clutch. The motor bike is leaning side of the turn, the body on other side to keep balance but by keeping the shoulders parallel with the handlebar; the legs are thus drawn aside.

In descent, the body leaves behind proportionally to the degree the slope.

A rise is carried out with dash followed by a regular acceleration of slightly sitting down in order to increase the adherence of the back tire. The legs continue to deaden the relief of the ground.

Elaborate techniques

The jump, called jump ,…

Extension…

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