The new BMW G 450 X Sport Enduro is a unique motorcycle that completely redefines enduro riding.
That’s because it’s been designed from the ground up to deliver the sort of off-road traction dreams are made of, with a brand new single-cylinder engine and a revolutionary swing-arm design. The result is a bike that is quite simply unstoppable.

1 Traction: Thanks to a revolutionary frame.
Unstoppable performance can only be achieved with original thinking, as seen in the mounting of the rear swing-arm of the G 450 X. Its pivot point shares an axle line with the drive sprocket, so ensuring that the length of the drive chain and as a result, the efficiency of the transmission is not affected by the compression and rebound of the suspension. The swing-arm is significantly longer than on other bikes with a comparable wheelbase, for maximum ground contact and traction on any surface. Finally, the ground-breaking frame features perfectly straight tubing, offering exceptional structural rigidity.

2 Unstoppable traction. Thanks to an outstanding engine.
The key to unstoppable performance is an unbeatable engine. An engine like the ultra-modern DOHC single-cylinder unit found in the G 450 X*. It is angled forwards,allowing for long, straight air intakes, which in turn makes possible an optimum location for the fuel injector and the two throttle valves. The engine provides punchy yet supremely controllable responses right across the rev range. In addition, the innovative positioning of the clutch directly above the crankshaft minimizes the amount of torque it has to handle, and as a result its size and weight can be significantly reduced.

3 Traction. Thanks to an uncompromising suspension design.
To be truly unstoppable, you need outstanding grip, which means maximum ground contact at all speeds and on all surfaces. The front of the G 450 X features a fully adjustable Marzocchi upside-down fork with 300 millimetres of travel, and effortlessly takes on even the bumpiest terrain. At the rear is a fully adjustable Öhlins monoshock suspension system, also fully adjustable and with 320 millimetres of travel.

4 Traction. Thanks to a perfect riding position.
Unstoppable performance is not just about the frame, engine and chassis. It’s also about the rider. The riding position, whether travelling uphill or down, sitting or standing, is also of vital importance to proper control of the bike. The G 450 X is exceptionally well balanced, with a slim body, and a long, flat seat. And for maximum freedom of movement, the fuel tank is located beneath the seat rather than in front of it.

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 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.