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EICMA: BMW G 450 X
Concept, requirements and features
During the last 80 years BMW Motorrad
has made off-road history time and time again. The marque is
now more closely involved in off-road sport than ever and is
launching an uncompromising, sport enduro for the attractive
450cc class.
The exclusively developed BMW G 450 X is an enduro sport for
some of most demanding competitive racing in the world. It is
a machine that is ready to compete the moment it leaves the factory.
The background to the development is the knowledge that competition-oriented
enduro motorcycles represent a parameter with growth potential.
Markets such as the USA, Australia and Spain already register
nearly traditional stable sales in the off-road sector.
BMW Motorrad wants to help shape and stimulate this (and other
markets) for the long term. Smaller volume off-road motorcycles
open the gateway to popular and professional motor sport as well
as offering enough potential to help the young generation to
discover the fascination of motorcycles.
The engine of the G 450 X features the latest fuel injection
and computer-controlled three-way catalytic converter. It is
Euro III homologated and already meets the rigorous current and
future vehicle emissions standards for sports events and road
vehicles. With these measures BMW Motorrad is taking a further
step towards public acceptance of enduro sports. The patented,
unrivalled technical features of the new BMW G 450 X make it
a driving force that contributes to the advance of technological
competition in its segment.
The introduction of the tough enduro BMW G 650 Xchallenge has
already pointed the way: with a frame and swing arm layout for
improved offroad traction, low weight, compact chassis, and dynamic
engine. The G 450 X goes even further and BMW is not content
with constructional features traditionally seen in the class.
High-tech solutions have been realised in the engine and chassis
design, in keeping with BMW's cross-country sporting tradition.
It is a machine that will give the marque a fascinating and exclusive
off-road profile.
The concept of the BMW G 450 X is based on keeping the mass concentrated
as near as possible to the centre of gravity and realising a
vehicle configuration that adapts perfectly to the requirements
of off-road sport.
The central element of this concept is the amalgamation of the
bearing axle of the rear-wheel swing arm with the axis of rotation
of the driving pinion. This ensures that there is no change in
the length of the chain on compression and rebound. The effects
of the final drive on the vehicle's response are therefore minimized.
Further consequences of this unequalled technical approach are
a noticeably longer swing arm (for the same wheelbase as other
machines) and, with it, maximum traction. This provides definite
advantages in enduro sports which exert extreme demands on rider
and machine.
Fundamental to the overall design is a saving in length through
the alliance of the swinging bearing and pinion rotation axis.
Not only does this enable a longer swing arm but the modern high-performance
DOHC single-cylinder engine, with an output of 50PS, is able
to be positioned further towards the rear. The cylinder has therefore
been angled more acutely towards the front, thus creating space
for long, straight intake tracts. In this way an ideal position
was reached for the fuel injection nozzle and dual throttle valve
fuel injection system. This contributed in adapting the engine
to meet the requirements of the Euro III exhaust gas norm
without loss of performance.
Further concept advantages include optimum protection of the
airbox and voluminous air flow because of its placement above
the motor and in front of the seat. One consequence of the centralised
concentration of masses close to the centre of gravity is that
the 8.5-litre tank is under the seat. The filler manifold is
located below an opening in the rear part of the seat. The reserve
function is signaled by a warning lamp in the cockpit.
The starter is placed in front of the engine. The easily accessible
battery is protected from dirt and sits directly behind the control
head in the upper triangular frame. The air filter is a square,
flat wet element fixed by a drawer mechanism that makes it easy,
safe, clean, and extremely fast to change. For this,the right
cosmetic tank cover (fixed with a quick-release fastener) is
removed and the air filter drawer pulled out.
The intake funnel is positioned at the height of the control
head whose high-lying position is advantageous in water splashes,
or wherever there is heavy dust. The seat of the BMW G 450 X
is made from special foam plastic. The foregoing of a cover,
and not having a substructure or sump as its base, brings weight
advantages.
Another distinctive construction feature is the relocation of
the clutch directly onto the crankshaft. A position that enabled
the ingenious frame construction the frame tubes were placed
directly ahead of the swing arm pivot, enabling maximum stiffness,
minimum weight and minimal use of material. The cooler had sufficient
space to be realised in one piece. This saved additional coolant
hoses and reduced weight important for an off-road motorcycle.
The development of the BMW G 450 X focusses on the ergonomic
shape and design of the active driving configuration. From the
steering head to the rear section of the seat the machine has
an extremely slender width exactly where the rider sits
and provides maximum freedom of movement. In a standing
position, the rider benefits because of the absence of a tank.
This point provides unrestrained clearance because the motorcycle
is appreciably slimmer.
The G 450 X is the first BMW enduro to be uncompromisingly developed
for professional competitive racing. The advantages of the unique
construction are evident in rugged off-road conditions. These
include the effective concentration of masses around the centre
of gravity; the engine effects eliminated by the unique swing
arm mounting; the resulting low wear of chain and pinion, and
extreme handling reminiscent of a 250 series motocross motorcycle.
Also notable are the prodigious tracking stability, low weight,
powerful engine and the high-technology spring elements. These
offer the ambitious enduro sports rider a number of package and
design benefits in hard competition, plus limitless riding pleasure.
A dedicated team of specialist engineers and mechanics, who have
also taken part in intensive off-road sport privately for many
years, has developed this new model for BMW Motorrad under the
motto "from passionate professionals for passionate professionals".
The BMW G 450 X weighs about 40 kilogrammes less than the G 650
Xchallenge for roughly the same output and is perfectly tailored
to the requirements of the ambitious and success-oriented enduro
sports rider. As a completely special and absolutely exceptional
motorcycle, the BMW G 450 X is a genuine sports machine that
has all parts required for MOT approval as standard. This means
that unlike other vehicles in the class it is possible
to ride the BMW G 450 X to the track on public roads.
The innovative, patented technology of the single-cylinder sports
enduro concept was put to the test in highly-competitive events
throughout the 2007 season by experienced and successful racing
professionals. These included such riders as Sascha Eckert, Simo
Kirssi and Joël Smets who harmonised and developed the concept.
The motorcycle comes ready for off-road racing and competition
and (with approval) public road use straight from the factory
without modification.
Thanks to great traction at low revs, smooth engine output, high
revving, superior riding qualities such as extremely light handling,
best balance in slow
"trial" sections, and enormous stability at high speed,
the professional, experienced or novice enduro rider will have
no difficulty in mastering the G 450 X motorcycle.
To corroborate the machine's extremely sporty enduro qualities,
BMW Motorrad's works racing team has already taken part in different
enduro sports during the test phase of the G 450 X. The team
will continue racing it in the Enduro World Championship of the
E2 class and/or the German Cross Country Championship (GCC).
The worldwide market introduction of the BMW G 450 X is scheduled
for the middle of 2008.
Model designation BMW G 450 X
The model designation G stands for a new Generation of sporting
motorcycles in the mid-range and lower capacity segments. It
is distinguished by its consistent lightweight, easy handling,
tracking stability, and safe riding qualities. For drive power,
the focus is placed on powerful, cultivated, dependable and economic
single-cylinder engines.
G stands symbolically for a well thought out General concept;
perfection in the performance of the whole machine and for the
harmony of all individual components. G also stands for Great
riding qualities and pure unadulterated riding pleasure.
The range of possible uses of the G models covers a wide spectrum:
from the light all-rounder, ideal for touring, to the agile supermoto
performer and the robust hard enduro right up to the genuine
sports enduro with competitive qualities. While the models of
the 650 series are based on a common technical basis, the high
performance G 450 X is the first machine of a motorcycle generation
that proves to be uncompromisingly competitive and success oriented.
Common to all G models is the high-grade substance of the product
and legendary BMW quality independent of where it is produced.
Specially tailored to differing riding styles, and the abilities
of the G 450 X, exclusive training and preparation will progressively
supplement the new motorcycle.
Development, technology and design
From a technical point of view the BMW G 450 X has no forerunners.
It is a brand-new development where features such as weight saving
and an uncompromising configuration for the requirements
of competition-oriented off-road racing were at the forefront
of the specification.
Test programme
Enduro racing places enormous stress on materials. The transition
to motocross sport is fluid and the machines, which are tuned
to the limits of performance, are pushed to the limit so that
technology can satisfy the highest demands.
Due to the extreme range of use, the trials of the G 450 X were
extremely complex and totally new paths had to be taken in some
areas. The testing included the toughest enduro performance with
metre-high jumps; freezing cold and extreme heat; water splashes,
and continuous racing
in extremely dusty conditions with sand and stone impacts. The
bike must be able to withstand all these conditions reliably
and sustainably. Hardly any other type of motorcycle is confronted
with such requirements in this combination.
The proving programme primarily included testing in a real competitive
environment and numerous test bench tests. Trials on special
test tracks were correspondingly extensive and intensive. From
the very outset this meant the BMW G 450 X had to prove itself
in the environment in which it intends to compete. This took
place on national and international enduro and motocross racing
tracks where the slightest weakness of rider or machine can lead
to defeat or failure.
Long-term trials on terrain in Spain and Italy continued the
overall programme right up to serial production.
Engine
The 449 cc single-cylinder DOHC 4-stroke motor of the G 450
X was developed by BMW. The compact cylinder head of the short-stroke
four-valve unit houses the technical elements of the K 1200 S.
For example, the intake valves are operated by follower valves,
and the outlet control is implemented by tappets. This is a space-saving
configuration distinguished by high engine speeds. Optimum performance
meets the requirements of the Euro III exhaust gas norm and is
realised by fuel-injection with oxygen sensor regulation and
a dual throttle valve system which ensure that the engine reacts
more sensitively to gas commands. The crankshaft and conrod are
fitted with rolling bearings and the weight-optimised two-ring
piston is forged.
A balance shaft effectively reduces the vibrations typical of
a single-cylinder engine. The constant mesh five-speed gearbox
standard throughout the 450 series was widely staggered
for optimum connections while racing. The primary coupling sits
directly on the crankshaft and is configured as a wet clutch
with a clutch diaphragm. In contast to conventional concepts,
the BMW G 450 X clutch is considerably more compact and has a
smaller diameter with the same number of discs. Contrary to the
conventional geared-down clutches, this is possible because the
clutch only needs to transmit a correspondingly reduced torque
on the transmission input shaft. The clutch is operated by a
cable.
The engine is fed with oil by a wet sump lubrication system.
Two oil pumps, a pressure pump and a suction pump use the same
volumes of oil to lubricate the gearbox and the crankshaft. The
two integrated oil sieves and oil filter are easy to access from
the left side of the engine. The volume of oil approximately
one litre can be checked via an inspection glass.
An intermediate shaft with integrated ventilation function transfers
the power from the crankshaft to the gearbox and this means that
the crankshaft of the G 450 X engine rotates backwards.
The cylinder is tilted forward by approxi-mately 30 degrees,
enabling the centre of gravity to be moved in the direction of
the front wheel thereby assisting the suspension. A further advantage
of tilting the cylinder is the creation of space for the intake
air ducting that can now come vertically from above, and virtually
straight, promoting optimum performance.
The engine of the BMW G 450 X, condensed into 12 : 1, is started
by an electric starter; an additional kickstart is unnecessary
thanks to a powerful battery and fuel-injection. An automatic
decompression function with a centrifugal force valve lifter
reduces the power demanded by the starter. Even when the machine
has to travel for longer periods at higher revs in difficult
and slow off-road sections, the engine is never excessively thermally
loaded thanks to its large-volume, single-piece water cooler.
A fan behind the cooler provides sufficient air flow rate at
low flow speeds.
The series exhaust system is made of stainless steel and the
catalytic converter is fitted in the silencer (absorption silencer).
For exclusive use in competitive racing, optional sporting end
silencers are offered as special equipment and it is possible
to switch to the extreme race mapping stored in the engine control
unit.
Despite the powerful alternator and electric starter, the high-performance
engine of the BMW G 450 X weighs no more than the aggregate of
competitor motorcycles (less than 30 kilogrammes). The exact
power and torque data are not yet fixed.
Chassis
The chassis of the BMW G 450 X is a completely new development
that uses selected high-quality components and materials. BMW
Motorrad's years of enduro experience aided the development of
the chassis. The main consideration in the geometry and overall
configuration of the chassis was to meet the especially high
demands of off-road racing. The results are excellent all-terrain
properties with ease of handling, great manoeuvrability and extreme
tracking stability.
Innovative frame concept
The frame layout is based on the experiences of the development
engineers; the know-how from competitive racing and its attendant
research and development work. The knowledge gained from earlier
rally sport activities was also incorporated. The frame of the
BMW G 450 X differs in principle from all the constructions of
competitor machines. In the main it consists of thin-walled,
but high-strength stainless steel precision tubes and is welded
to the node points with forged parts deployed for the purpose.
No additional surface treatment is necessary. The entire main
frame weighs a mere 8.6 kilogrammes and is distinguished by excellent
rigitity.
The lower bow of the frame tubes runs directly from the swinging
axle straight to the steering head. The upper bow creates a direct
connection between the suspension strut mount and steering head.
The wheel forces are braced centrally on the frame over the suspension
strut so that the light rear frame is bolted to the main frame
and is formed by aluminium square profiles and only needs to
bear the weight of the rider. All in all this construction enables
the optimum flow of force, requiring minimum use of material,
and allows an unrivalled rigidity to weight ratio.
The 18-inch rear wheel is suspended in a robust dimensional two-arm
swing arm made from aluminium square profiles which supports
a directly linked Öhlins central suspension strut with a
generous spring travel of 320 mm. This high-technology element
is variably adjustable in pressure and outward stroke damping
as well as in the spring pre-tension. The suspension of the 21-inch
front wheel is undertaken by 45mm upside-down forks by Marzocchi.
This absorbs even the roughest ruts with a spring travel of 300mm
and is fully adjustable.
A powerful brake system with double-piston floating caliper,
from Brembo, ensures the deceleration of the BMW G 450 X. The
front single brake disc has a diameter of 260mm, and the rear
disc measures 220mm.
In order to live up to the harshest off-road conditions, the
BMW G 450 X has a light, impact resistant and highly stable plastic
underride protection fitted as standard. This has already proved
itself in racing. The motorcycle also has a double-butted Magura
aluminium handlebar that guarantees optimum control on all terrain.
Patented swing arm mount
The real finesse in the chassis sector and a unique feature
of the BMW G 450 X is the coaxial mount of the swing arm and
chain pinion. The swing arm pivot has been mounted through the
hollow gearbox outlet so that there is no change in the length
of the chain on compression and rebound over the entire spring
travel. The chain tension remains constant, independent of the
compression position; the pinion, chain and chain ring are subject
to less wear than in conventional constructions. A positive effect
on the riding characteristics is that the effect of changing
loads on the powertrain is now noticeably reduced.
Thanks to the patented coaxial mounting of the swing arm and
drive chain pinion, plus a wheelbase at competition level, the
swing arm is 30mm longer, markedly improving traction properties.
The rear wheel remains more in contact with the ground in all
situations and retaining the driving force on all types of terrain.
Also, compared with other machines, a significantly greater length
adjustment range of the rear wheel results. This allows different
pinion chain ring combinations on the same chain.
When a pinion has to be replaced, the swing arm must be removed.
However, in comparison to conventional concepts, this is not
a particularly time consuming task. An experienced mechanic can
replace the pinion in about 15 minutes and, because of the
much lower wear of the entire final drive, the pinion needs to
be replaced less often then on other competition machines.
Design
The look of the BMW G 450 X is unmistakenly BMW Motorrad.
The dynamic 'flyline' allows the new motorcycle to be identified
as a typical member of the BMW enduro world. The most striking
element is the typical family beak the most distinguishing
characteristic shared by all GS models.
The visual appearance also expresses pure sporting performance
with associated aggression. This results in the look and feel
of a fascinating vehicle that suggests the right to ride and
to win in competitive races.
The colour concept of the G 450 X is oriented to the G 650 Xchallenge.
The standard colour is 'racing white' with blue accents, typical
of BMW, which highlights the affiliation to the G model family
and the new, sporty enduro line from BMW.
Technical data
The exact technical data of the BMW G 450 X has not yet been
finalised as the machine will not be available to purchase until
the middle of 2008. The maximum output is around 37kW (50PS)
with a best torque value of approximately 48Nm. The overall weight
with full tank is approximately 120kg which means that the BMW
G 450 X is lighter than the current best weight values in its
class. This value is all the more impressive because the machine
boasts fuel injection, catalytic converter, electric starter
and Euro III homologation. The exact geometrical data of the
chassis is subject to last minute fine tuning and will be announced
at a later date.
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