Présentation en ANGLAIS de la conception de la XTZ 1200

Pour les anglophones.
C'est bien sûr du marketing mais il y a des détails intéressants.

Engine features

1. Newly developed liquid-cooled, 4-stroke, in-line 2-cylinder engine
The new XTZ1200's liquid-cooled, 4-stroke, in-line 2-cylinder, 1199cc
fuel injected engine with a 2-axis primary balancer has been developed
to provide outstanding performance in long-distance touring. With a bore
x stroke of 98.0 x 79.5mm and a compression ratio of 11.0:1, it
produces a max output of 80.9kW (110PS) @ 7250rpm. This bore × stroke
spec is set to achieve the target output from a compact combustion
chamber and contributes to the slim engine size.

2. Compact combustion chamber with twin spark plugs To achieve
outstanding combustion efficiency, the bore diameter was kept modest and
two spark plugs were fitted to each cylinder. The valve positions and
shape of the upper surface of the pistons were optimised to fit the twin
spark plug design. Compared to a single-plug combustion chamber with
the same bore diameter, the twin plug spec shortens the required flame
diffusion distance and speeds combustion time, thus contributing to an
outstanding torque character.

3. Downdraft air intake and 26-degree forward-inclined cylinder One
merit of the in-line 2-cylinder engine format is that it provides
greater freedom of positioning for the intake system and fuel tank. The
layout adopted on this model takes advantage of this with a design that
optimizes both intake efficiency and chassis dimensions.

First of all, in order to realise a downdraft type intake that heightens
intake efficiency, the cylinders are given a 26-degree forward incline
and the air cleaner is positioned upward from the cylinders. And this
air cleaner has a very space-efficient hemispherical form.

Optimising the relative positions of the various components has
contributed to centralisation of machine mass while also helping
achieved the desired short wheelbase dimension.

4. 270-degree crank
A 270-degree crank has been adopted with the aim of a good balance of
torque and traction and for improved drivability over the entire speed
range. Compared to the conventional 360-degree crank (in which the
cranks of the left and right cylinders revolve in unison), the
270-degree crank means that the two cranks revolve with a 90-degree (1/4
of a revolution) offset between them in terms of connecting rod motion.
This maintains a good crank balance and minimises the effect of
inertial torque to accentuate easy-to-use torque and rear wheel
connectivity. The firing intervals are at the 270- and 450-degree
points.

One of the features of the new engine is the compact, lightweight design
and layout of the shafts and periphery components in order to get room
for the oil tank inside the crankcase.

This engine adopts 2-axis balancers with an optimised relationship
between the balancer axes and the pumps, etc. In specific terms, 1) the
axis of the forward balancer is positioned along the line where the
upper and lower sections of the crankcase meet. This makes it possible
to eliminate the shaft supporting the balancer and thus reduce weight
and make more efficient use of space. Also, 2) the water pump and the
forward balancer share the same axis, and 3) a design is adopted in
which the oil pump is driven off the forward balancer shaft to also
contribute to reduced weight and compactness.

Crank offset explained
Torque is a force consisting of two components, the force created by
combustion, called “combustion torque,” and the force created by the
reciprocating motion of the piston, called “inertial torque,” and
together that constitute the total torque created by the engine, called
the “composite torque.” What is generally referred to as “torque” is
actually this “composite torque.”

The “combustion torque” is the torque resulting from combustion and it
is directly related to the rider's throttle work. In contrast, the
“inertial torque” is dependent on engine rpm and is created by the
revolutions of the crankshaft. Therefore it is not directly connected to
the rider's throttle work. The “inertial torque” fluctuates due to the
fluctuations in crankshaft revolution speed.

The inertial force of the moving piston varies in accordance with the
position (angle) of the crank, with the inertial force working upward
when the crankpin is in the upper half of its revolution and working
downward when the crankpin is in the lower half. In other words, there
are times when the inertial force causes the revolving speed of the
crankshaft to quicken and times when it causes it to slow. This is the
fluctuation in inertial torque. Also, in the case of a 360-degree crank
2-cylinder engine, the fact that the crankshaft and connecting rods of
the right and left pistons are moving in unison, the amount of
fluctuation in revolution doubles.

With an in-line 2-cylinder 270-dregree crank engine, the 90-degree
offset (1/4 of a revolution) between the movements of the two connecting
rods reduces the inertial torque to almost zero. This gives the
composite torque and the combustion torque virtually equal values. As a
result, this contributes to more linear response to the rider's throttle
work and superior traction characteristics.

5. Oil tank in crankcase for compactness and lower centre of gravity
The lubrication system is a dry sump type and a structure with the oil
tank built into the crankcase has been adopted to enable the desired
minimum ground clearance. This design with the oil tank built into the
crankcase is one of the distinctive features of this new engine.

The adoption of a design with the oil tank positioned below the
transmission shaft eliminates the need for a separate oil tank and
piping, which contributes to centralisation of machine mass and a lower
centre of gravity. In combination with the effects of the previously
mentioned balancer axis positioning, this further contributes to a more
compact engine design.

6. YCC-T with traction-control function developed based on MotoGP
technology
A 12-hole injector is mounted in the intake manifold to inject a finely
atomised spray of fuel at high pressure to fill the combustion chamber
with the air-fuel mixture. This helps achieve excellent combustion and
improve engine response. It is also an engine with outstanding
environmental performance as well.

As a throttle valve controlling to regulate intake air volume, YCC-T
(Yamaha Chip Controlled Throttle) is adopted. YCC-T monitors the rider's
throttle work and that input is processed by the ECU to calculate the
ideal throttle valve opening in real time and send those signals to the
servomotor operating the throttle valve to control the volume of intake
air. The high-speed calculating function employed in this system renders
calculations at increments of approx. 1/1000th of a second and is based
on the same technology that has been used in this system since its
adoption on the 2006 model YZF-R6.

What characterises the YCC-T adopted on XTZ1200 is the addition of a
traction control function, based on technology fed back from the YZR-M1
MotoGP racer. Input from the front and rear wheel speed sensors is used
to detect rear wheel spin, which is then processed instantaneously by
the ECU and signals are sent to comprehensively regulate (1) YCC-T (2)
ignition timing and (3) the volume of fuel injection.

This YCC-T with traction control thus serves to optimise traction at the
rear wheel and minimise rear-wheel sliding, negative effects on machine
attitude, especially on road surfaces with poor traction and during
acceleration, and provide better overall drivability, especially during
acceleration on road surfaces with poor traction, and provide better
overall handling.

The traction control system also features a choice of two operating
modes, a TCS1 (strong) and TCS2 (limited), as well as an Off option for
the rider to select from with a button on the side of the meter panel.

The TCS1 is the standard traction control mode while the TCS2 is a mode
with limited traction control that lets the rider enjoy more of the
inherent machine movement. When Off is selected the traction control
system does not function at all. The currently operating mode can be
verified by the indicator on the meter panel.

The ability to select the desired traction control mode based on road
conditions or rider taste is one more way this model supports the
rider's enjoyment of touring performance and running performance.

7. Yamaha D-MODE select function
Equipping XTZ1200 with the D-MODE select function provides the capacity
to adapt to an even wider rage of riding conditions. This is another
feature enabled by YCC-T to optimise throttle valve opening. This mode
selection device lets the rider choose between the S Mode that tweaks
engine performance and response to provide a sportier ride and a T Mode
tailored for ease of use in touring or around town riding. It offers
another set of rider choices to accommodate different preferences and
riding conditions. The two modes can be selected with a switch on the
handlebar.

8. Shaft drive with hypoid gear
In order to achieve a high level of reliability in a variety of
conditions, a low-maintenance shaft drive unit is adopted. This shaft
drive unit is the first on a Yamaha motorcycle to use what is called a
hypoid gear. This compact-design unit helps to reduce un-sprung weight
and mechanical noise as well.

In a conventional motorcycle shaft drive mechanism, the pinion gear (on
the shaft axis) and the ring gear (on the bevel gear axis) mesh in a
linear relationship in order to achieve an efficient transfer of drive
force. However, this arrangement requires a large ring gear in order to
achieve the necessary reduction ratio, which causes increased weight.

The hypoid gear used on this model features an offset between the pinion
gear and the ring gear axis that enables sufficient width of meshing
gear teeth width (length) and provides the advantage of enabling the
unit to be designed with a smaller ring gear diameter. (Approximately
10% smaller diameter than a conventional type for the same reduction
ratio, enabling a compact rear gear case of just 176mm diameter.) This
enables a reduction in rear un-sprung weight while contributing to
excellent running stability.

9. Compact elliptical short muffler and 3-way catalyser
In order to provide a high level of exhaust efficiency and a pleasing
exhaust sound, a 2-step expansion, 2-into-1 muffler is adopted. At the
point where the two exhaust pipes meet a honeycomb type catalyser coated
with precious-metal catalysing elements is positioned to provide
excellent exhaust cleaning performance. For the muffler, a short,
vertically elliptical cross-section muffler that contributes to a
slimmer body design and better centralisation of machine mass is
adopted.

The carbon monoxide (CO) and hydrocarbons (HC) resulting from the
burning of gasoline in the engine are cleaned from the exhaust by a
chemical reaction (oxidation) occurring when they come in contact with
the platinum and rhodium elements in the catalyser. The nitrogen oxides
(NOX) that are produced from naturally existing nitrogen (N) and oxygen
in the air as a result of the high temperatures caused by combustion of
the gasoline are cleansed by a chemical reaction induced by contact with
the rhodium element that returns them to their component elements (N)
and (O) in a process called ‘reduction'.

To achieve the desired levels of this oxidation and reduction processes
to clean the exhaust, the first requirement is that combustion occur
with the optimum air-fuel ratio. For this reason, an O2 sensor is
mounted in the exhaust system to monitor the amount of oxygen remaining
in the exhaust and this data is fed to the fuel injection system which
is then fed back to adjust the fuel injection volume (in a process also
called feedback control) to constantly maintain the optimum air-fuel
ratio.

On the XTZ1200, with the unique exhaust pulse resulting from the
270-degree crank engine, an O2 sensor is fitted for each of the two
cylinders in order to provide highly accurate information about
combustion conditions in real time and enable feedback that ensures
control accuracy, thus achieving eco-friendly performance of a high
level.

10. Other engine-related features
1) Aluminium forged piston
A forged piston is characterised by a finer, more consistent metallurgic
matrix that has greater strength and thus enables a lighter piston
design that in turn reduces reciprocating mass, which means less
vibration.

2) Carburised connecting rods
Carburising increases the carbon content in the surface area of the
connecting rods to increase mechanical strength and ensure a high level
of reliability.

3) Auto-decompression
A decompression mechanism that releases air compression in the cylinders
when starting the engine is adopted. This helps reduce the size of the
starter assembly that otherwise tends to be large on a
large-displacement model.

4) New-design transmission and clutch
A newly designed wide-ratio 6-speed transmission is adopted to enable
full enjoyment of torque-y engine performance from the low-speed range. A
newly designed clutch is also adopted.

5) Low centre-of-gravity engine mounting
A compact design has enabled the engine mounting system with a lower
centre of gravity. A crankshaft axis height of just 381.9mm from the
ground has been made possible despite a minimum ground clearance of
205mm.







__________________

Chassis features

1. New frame made of high-tensile steel pipe
The new model adopts a newly designed frame made of high-tensile steel
pipe. With excellent rigidity-strength balance, the new frame
contributes to a ride with softness well suited to the torque-y engine
performance to help provide comfortable, enjoyable drivability, even in
long-distance riding.

Made of steel with a precisely controlled carbon content, the
high-tensile pipe provides good strength balance and flexibility. The
design is intended to ensure good running performance even when carrying
a load of luggage on the rear. It is also a design that makes positive
use of the engine as a stressed member of the chassis.

The two backbone forms extending from the right and left of the head
pipe are designed to accommodate the low mounting position of the
engine's cylinder head and crankcase. It also helps enable a fuel tank
design with a lower centre of gravity.

At the same time, the design makes it possible to achieve a
straight-line layout for the air-cleaner box, throttle body and intake
vent for the cylinder heads in front of the fuel tank. This is also a
structure that enables easier access to the engine's peripheral
components during maintenance and servicing.

The rear frame is made of expanded aluminium pipe in order to reduce
weight and thus contribute to centralisation of machine mass. In
addition, it is designed for a high level of rigidity to help prevent
damage in the case of falls and the harsh conditions of running with a
pillion passenger and outfitting the machine with three pannier cases.

2. Front fork with 43mm diameter inner tubes
In order to provide natural handling in everything from long-distance
running to riding on unpaved roads and mountain roads, and upside-down
telescopic type front suspension with 43mm diameter inner tubes is
adopted.

In addition to providing sufficient stroke and rigidity, the telescopic
type fork has a character that allows the rider to enjoy cornering while
sensing the road surface conditions. On the XTZ1200, this front
suspension has been tuned with settings that provide the desired
rigidity while bringing out the type of linear performance and
gentleness that only an upside-down fork can offer. In order to
compensate for difference in weight carried and the possible presence of
a pillion passenger, this suspension is fully adjustable for initial
load and compression/rebound stroke damping force.

3. Low-pressure cast long swingarm and rear suspension
The swingarm is made by the metal-mould low-pressure casting method.
Parts made by the low-pressure casting method contain virtually no
impurities in the cast metal and can provide a superior
strength-rigidity balance because less gas enters to form air pockets in
the cast metal. Due to the fact that this model mounts a new engine
that is shorter in the forward-rear dimension, it was possible to give
the swingarm a length of 580mm that contributes to more stable machine
movement and outstanding running/handling performance.

The rear suspension is a linked type Monocross suspension. It is
adjustable for initial load and rebound-stroke damping force. Also, in
order to make it easier to adjust the suspension to accommodate changing
running conditions, the initial-load adjustment mechanism is designed
so that adjustments can be made easily without the use of any tool.

4. New-design side-mounted radiator that contributes to cooling
performance and handling stability
A side-mounted radiator is adopted. It is mounted on the left side of
the machine in a design that provides the necessary cooling performance,
helps enable a short wheelbase and contributes to centralisation of
machine mass. Despite being a compact double-core type radiator with a
core size of 320mm x 170mm, 2.1LLC litre capacity, it provides
outstanding cooling performance thanks to the optimised air intake vents
and the added effect of running wind directly cooling the cylinders and
head.

In this design, the airflow runs through the inner spaces of the machine
to the radiator and is then released out to the side. This reduces the
effect of radiator heat on the rider to make the ride more comfortable
and enjoyable.

On the opposite (right) side of the machine the electrical components
are grouped along with the battery, which is one of the weightiest
components on the machine. This layout helps to reduce the overall
length of the harness, reduces weight and contributes to centralisation
of machine mass. It is also a design that takes into consideration ease
of serviceability when checking the electrical components.

5. ABS and Unified Brake System (front-rear unified brake system)
Two distinct features that contribute to touring performance are the
Unified Brake System (front-rear unified brake system) and ABS adopted
on this model. Unified Brake System is a system in which operating the
front brake lever also initiates the application of braking force by the
rear brake. When the front brake is operated, electronic control comes
into play to regulate the amount of brake force generated by the rear
brake based on the strength of the front brake application (hydraulic
pressure), running speed and the amount of added weight the machine is
carrying. As with a conventional ABS equipped machine, the ABS function
comes into effect to prevent wheel locking on slippery surfaces where it
is easy to lose tyre grip.

This system functions to provide a more enjoyable ride especially while
standing when it is more difficult to perform delicate rear brake (foot)
operations. To accommodate pillion riding or riding with a considerable
load of luggage, this Unified Brake System is designed for highly
precise control of the brake force applied by the rear brake.

The system is also designed to meet the needs of off-road riding where
the rear brake is used actively to maintain the stability of machine
attitude (lean, etc.). In short, the system is designed so that the
Unified Brake System function is cancelled at times when the rear brake
is applied before the front brake.

Plus a linear-control ABS system is adopted. It is a system that
supports the rider's braking operation in a variety of situations such
as at times when sudden braking is necessary or when there is a sudden
change in road surface conditions.

In this ABS unit, the ECU and hydraulic body are combined in a single
integrated unit for greater compactness that increases the freedom of
layout while contributing to centralisation of machine mass. Also, the
system uses the same front and rear wheel sensors as the traction
control system.

The ABS system's ECU receives information from the front and rear wheel
sensors about wheel rpm and calculates in real time the wheel speed and
rate of deceleration, machine running speed and slippage. When slippage
and wheel deceleration rate surpass the determined levels, the system
diagnoses a wheel locking tendency and sends signals to the hydraulic
control unit. Based on these signals from the ECU, the hydraulic control
unit reduces hydraulic pressure when a locking tendency occurs and
increases the hydraulic pressure again when the locking tendency is
resolved. The repetition of this process makes it possible to provide
braking without wheel locking.

The system adopted on XTZ1200 is the most advanced type with
improvements particularly in the feeling when the ABS function goes into
effect. It is a linear control ABS system with step-less, infinitely
variable hydraulic pressure adjustment to provide the appropriate amount
of pressure based on wheel lock conditions and force of lever
application in order to achieve smooth braking.

The front brake uses a 310mm rotor with wave-pattern and opposed-piston
callipers. The rear brake has a 282mm rotor with piston-slide type
callipers.

It should also be noted that the systems are designed with the Unified
Brake System function built into the ABS unit and no Unified Brake
System specific parts on the callipers. This helps reduce un-sprung
weight and contributes to excellent handling agility.

6. Vertically elongated fuel tank that contributes to centralisation of
machine mass
A large-capacity 23-liter fuel tank is adopted to accommodate long
distances between fuel stops. By positioning the frame's tank rail low
it has been possible to adopt a vertically elongated fuel tank design
that fits behind the air cleaner and cylinders with a sense of
consolidated mass. Increasing the efficiency of the volume/surface area
ratio has also helped to reduce unit weight. This layout promotes
centralisation of machine mass and minimises the effect of changes in
the fuel level on the running/handling feeling.

7. Double T type aluminium rims and spokes
The aluminium rims are specially designed for mounting tubeless tyres
and feature two rails (Double T type) on the inside of the rim side of
the narrower front wheel. These rails support the L-shaped ends of the
spokes, while in the hub side the spokes are attached with a tightening
nipple structure. This enables the setting of an optimum spoke angle to
provide reliability with regard to shocks from the road and the rigidity
necessary for good handling performance.

On the rear rim with its added width, only one rail is necessary. The
tubeless tyre sizes are 110/80R19MC 59V for the front and 150/70R17MC
69V for the rear.

8. Solenoid operated Hi-Lo switching projector type headlight
The newly adopted projector type headlight on this model features a
solenoid operated shade piece that moves up and down to set the high
beam and low beam. In this way, the same projector headlight provides
both high and low beam, thus ensuring good forward illumination and
enabling a more compact front assembly. It is the same mechanism used on
the headlight of the '09 model YZF-R1.

At the rear, an impressive LED taillight is adopted.

9. Adjustable seat, 3-way carrier
To ensure greater comfort in long-distance riding and ease of leg reach
to the ground, a front-rear divided seat is adopted that features height
adjustment (2-level adjustment with a height difference of 25mm) for
the rider's seat.

The standard equipment plastic resin carrier is a 3-way carrier type
designed to accommodate a wide range of uses. The three patterns are: 1)
Standard form
2) Fitted with a top case (option) and
3) A flat carrier surface extending to the pillion seat area.


In the standard form 1) the carrier can be used with a pillion rider
aboard. The top case form 2) accommodates a top case (option) with no
special attachment parts necessary. In the flat carrier form 3) the
tandem seat is removed and the position of the carrier adjusted to form a
single extended flat carrier surface. Also, this carrier surface forms a
nearly flat extended surface when side cases (option) are mounted on
either side.

10. Handlebar and footrest designs to accommodate a variety of riding
conditions
Design efforts have been made to accommodate the various type of riding
positions involved in long-distance and off-road riding. Particular
attention is given to the handlebar position, angle of handlebar bend,
inward and downward, to accommodate both the sitting position and
posture of long-distance riding and off-road riding in the standing
position.

What's more, the footrests have been designed not only with regard to
shape and size but also fitted with a specially designed hollow rubber
insert for the upper surface of the footrest. When the rider is seated,
this rubber pad provides a cushioning bulge. Then, when the rider stands
during off-road riding, the pad flattens to enable boot sole to come in
contact with the full surface of the footrest to the outer metal
portion for better machine hold.

11. Abundant range of options
To answer the needs associated with an adventure tourer model like this,
a lineup of specialised option parts and components has been developed
simultaneously with the XTZ1200 to be sold as Genuine Yamaha Parts and
accessories. These options include the following.
1) Fog lamp kit
2) High windscreen
3) Top and side cases
4) Steel pipe engine guard (protecting the cowling and the sides of the
engine)
5) Grip heaters
6) Headlight protector and
7) Large aluminium skid plate (protects engine bottom).

Super Ténéré development: Evolution of a Legend
The first time the Ténéré name was used on a Yamaha motorcycle was with
the XT600Z Ténéré of 1983. This model was a further development of the
adventure machine XT500, and giving it the name of the Ténéré Desert
that formed part of the Paris-Dakar course was symbolic of Yamaha's
determined challenge to conquer that rally.

The aim to increase the scale of off-road performance led to the birth
of the larger displacement twin-cylinder XTZ750 Super Ténéré in 1989.
This XTZ750 Super Ténéré and the successive Yamaha rally machines went
on to a number of dramatic Dakar Rally competitions and make the Ténéré
name synonymous with the great challenge of the Dakar Rally for many
adventurous riders.

In developing this new model, our development team made its fundamental
aim the continuation of this Ténéré spirit in the hearts of adventurous
riders while developing a machine with the high level of potential
necessary to meet the demands of grand-scale intercontinental touring.

Building on the base of off-road running performance that has been the
Ténéré signature until now, a higher level of performance on mountain
roads has been developed, as well as greater comfort for long-distance
rides. What we sought was a fusion of these three types of performance.
In this sense you can say that we undertook the development of an
ultimate all-rounder that goes beyond what would have been possible with
simply a further development of the existing Super Ténéré.

Ténéré means off-road riding When we rode across the European continent,
what we recognised was the desire for plenty of power. For example, we
felt the desire for the kind of performance that lets you accelerate
with enjoyable power from a high gear without downshifting while riding
on secondary roads. From the beginning the development team imagined the
power unit should be an in-line twin engine of 1000cc or more, but it
was by no means decided that it should have a 270-degree crank.

There is certainly appeal in the smooth engine that comes from a
360-degree crank. But there is also a strong appeal in the traction that
a 270-degree crank provides.

We took on the very difficult challenge of exploiting the positive
characteristics of a 270-degree crank engine while also getting closer
to the smooth feeling of a 360-degree crank. Our aim was a 270-degree
crank with a new flavour.

First, a prototype was constructed. This was a process of confirming the
concept and directions for development. This represented Yamaha's first
attempt at developing a twin-cylinder 270-degree crank engine of over
1000cc. The biggest hurdle to overcome in this task was how to balance
the opposing elements of high power output and lightweight. Then we
considered what technologies and methods to use in order to build in a
high level of rider-machine communication on top of that.

We also concentrated on achieving good off-road performance from a litre
machine. We considered the possibilities of drivability unique to a
litre machine with its powerful torque unprecedented in previous
off-road models. One device we chose to help achieve this was traction
control. Our development team decided to adopt a two-mode (with OFF also
possible) system to enable the rider to adjust the control function to
fit different riding conditions and personal preferences.

We also took into consideration the fact that it is difficult to use the
rear foot brake when riding in the standing position in off-road
riding. To support the rider with greater ease of use in that type of
riding condition, we adopted a Unified Brake System. This system
activates an appropriate level of rear wheel braking based solely on the
rider's input on the front brake lever, without use of the rear brake
pedal.

Ténéré means mountain road performance
One of the challenges and great joys a continental tourer model can
bring is crossing mountain ranges. But crossing mountain passes can
bring great changes not only in altitude but also in weather and road
surface conditions. Here, you want a motorcycle that provides the
traction the rider expects and anticipates during cornering. The
270-degree crank engine is one that delivers more positive combustion
torque that contributes to good traction characteristics while also
giving a pleasing sense of engine pulse. Together these qualities help
the rider enjoy cornering more fully and positively.

One of the key points in achieving our project goal of a 270-degree
crank engine with smoothness close to a 360-degree crank was the
adoption of the Yamaha Chip Controlled Throttle (YCC-T) with special
settings tailored to the 270-degree crank. Another point involves the
adaptation and optimisation with the shaft drive. One of the
characteristics of shaft drive is the ability to expand the range of top
gear toward the low rpm end. In other words it can be used to bring out
power development character that doesn't quit, and a feeling of too
sharp response is avoided.

We began the development with comparison tests between a 270-degree
crank engine with shaft drive and one with chain drive to determine the
right directions for development. After that repeated analysis and
riding tests led us to optimum specs for the middle gear damper and
changing the spring load and spring rate to optimise the damper
characteristics.

This combined with the optimized YCC-T settings to successfully achieve
performance with both the traction made possible by a 270-degree crank
and a feeling closer to the smoothness of a 360-degree crank engine.
Indeed, what we achieved was a 270-degree crank engine with an entirely
new flavour.

One of the basic factors in achieving light and pleasurable cornering
performance in a motorcycle is designing the engine and chassis for good
centralisation of machine mass. Even for a continental tourer model
with a displacement of 1000cc or more, the rider naturally wants the
agility and performance to be able to actively enjoy cornering. That is
why this engine has been designed in all aspects for optimum lightness
and compactness. For the dry sump lubrication system adopted to help
achieve the desired minimum ground clearance, a tank-in-case dry sump
system is adopted to move the initially separate outside oil tank into
the crankcase and thus contribute to better centralisation of mass. This
was Yamaha's first effort to design this for a public road-legal
on-off-road production model.

For the engine balancer an innovative 2-axis type was adopted. Greater
compactness and centralisation of mass were achieved with a design where
the front-side balancer shares the same axis with the water pump and
other measures. Further design improvements throughout the chassis also
contributed to centralisation of machine mass. Representative among
these is the adoption of a side-mounted radiator design, which
contributes to improved front-rear centralisation of mass while also
helping to achieve an optimum wheelbase dimension. All of these are
design measures aimed at achieving a higher level of rider-machine
communication through the total performance package, from the engine to
the detail components of the chassis.

Ténéré means long-distance touring
What riders want in a long-distance touring machine is good on-board
comfort (seat cushioning, air protection, comfortable riding position,
etc.) a comfortable ride (suspension, vibration, sound, etc.) and good
rider protection (wind, splash protection). In the development process
these basic long-distance tourer qualities were tackled first of all.
The twin headlights are not simply a symbol of Yamaha sport bikes but
also, in connection with the adjoining front cowl, help in limiting the
back-swirl of wind at the rider's chest. This also combines with the
separate (two-part) seat design, with its new shape, cushion and cover
material, to help create a comfortable rider space.

Another focus of development efforts for the XTZ1200 was the riding
position. In cross-continental touring, one is certain to encounter
various types of road-surface conditions. In some off-road riding in
particular, the rider will choose to ride in the standing position for
considerable periods. In light of this, the handlebar height, angle of
downturn and inward bend have been set to best accommodate both standing
and seated riding positions.

For long continental touring trips over numerous days, load-carrying
capacity is another important factor. Generally speaking, in order to
obtain good handling performance while carrying a full load, the chassis
must have the right level of rigidity and strength.

What we focused on was achieving a design that enables a near
duplication of the solo-riding handling characteristics under different
load conditions, including when riding with a pillion rider or a full
load of luggage. The idea was that even if the rider will inevitably
feel the added weight when carrying luggage or a pillion rider on the
machine, it is still possible to maintain the same solo handling
characteristics.

The riding environment and the rider's condition are constantly changing
elements. So we adopted a system that provides a choice of T (Touring)
Mode and S (Sports) Mode. There are times when you want to ride
seriously and other times when you just want to enjoy the scenery as you
ride, and this function fulfils those needs.

Test team analysis
The XTZ1200 owes much to the DNA engrained in Yamaha adventure bikes
from more than 30 years of development since the original XT500.

One example of this DNA is the running test method we call “team test
riding.” In developing running performance, the repetition of analysis
and actual running tests is everything. In many cases, analysis may
produce the desired performance specs for things like rigidity and
control maps, but when tried in actual track tests it is found that
further perfecting and adjusting are necessary. Even if the desired
rigidity is achieved, it may be affected by factors like the points of
flexibility of the frame, characteristics of the alloys used or slight
differences in the ECU mapping.

Sometime solutions can be found through the intuition of experienced
engineers, but what Yamaha put most trust in is the “team test riding”
process, in which five or six test riders work as a team taking turns
riding the machine and then together discussing their evaluations or
issues to be worked on further. No matter how good a test rider may be,
they are still human and there will inevitably be some things that they
don't notice. But working together as a team ensures that someone will
notice what another did not, and by discussing together, they will
gradually bring the machine to the point of having the right handling
performance.

On the other hand, XTZ1200 also has some unique and highly detailed
design elements. The rubber pad on the upper surface of the footrests is
hollow and arched to provide greater comfort. But when the rider stands
up on the footrests to manipulate the bike in demanding off-road
situations, the rubber pads flatten so the sole of the rider's boot
comes in contact with the surface of the footrest, including the outer
aluminium rim for better hold. This is a design detail specifically for
on- off-road riding. And, riders who actually use this model for
intercontinental riding will discover more of these design details.

Comment by the XTZ1200 development Project Leader, Mr. Ikuo Ishizuka.
“We don't think of the XTZ1200 as a motorcycle in the usual sense of a
product of industrial manufacturing. We feel that we were given the
chance to produce something that embodies the dreams of riders like
intercontinental touring and, when used, will be a machine that creates
Kando* and irreplaceable memories for them. That is why we tried our
best to build a dependable partner that will perform beyond the rider's
expectations in all of the different types of adventure riding
situations we could imagine. So we used our experience and the latest
technologies to build as much performance, functionality and reliability
as well as the sensual performance we built into it. I hope the XTZ1200
will help riders realise their greatest riding dreams.”

* Kando is a Japanese word for the simultaneous feeling of deep
satisfaction and intense excitement that people experience when they
encounter something of exceptional value.

my teatcher is rich and my flowers are beautyfull .

cré vin' diieu la perfide Albion attaque....

eh oh j'ai lu Harry Potter en British moi ! enfin le premier chapitre :( :(sifflote: