2009 BMW G 450 X
Concept, requirements and
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 de¬manding
competitive racing in the world. It is a machine
that is ready to compete the moment it leaves the
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
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
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
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
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 grav¬ity;
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
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
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
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.
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
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
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.
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
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 sys¬tem 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
hen 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.
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
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.
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.