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Engine management is provided by BMW BMS-C II electronic
engine control responsible not only for the concept of manifold injection, but also
for the dual ignition system. Indeed, BMS-C II engine management even features
model-specific control maps tailored to the various motorcycle concepts.
And thanks to the all-new stainless-steel exhaust complete with its oxygen
sensor and three-way catalytic converter now moved higher up than before,
as well as the precise engine set-up, the short-stroke power unit significantly
outperforms the EU 3 emission standard.
The proven valve drive system with its timing chain, two
overhead camshafts and cup tappets, as well as the aluminium radiator cooling
system, all remain unchanged. The gearbox likewise remains the same as before,
while the final drive ratio on the chain sprocket has been modified, with a
15-tooth pinion and a 47-tooth sprocket on the G 650 Xchallenge providing a
shorter ratio than on the other two G 650 X models with their longer 16:47
ratio. The different roll circumference on the rear tyres, finally, also affects
each model’s riding dynamics.
Yet another new feature is the dry sump oil tank to the left
behind the cylinder, contributing to the perfect concentration of masses around
the motorcycle’s centre of gravity and thus promoting the unique handling of each
model to an even higher standard.
Ease of maintenance with service intervals of 10,000
kilometres or 6,000 miles unusually long in this segment remains at the same
high level as before.
Highly stable lightweight frame made of steel and aluminium.
The particularly light frame is the same on all three models
in the G 650 X series and is made up of four highly stable modules: The welded main
frame made of steel profile sections, aluminium castings bolted on to the
main frame around the swing arm mounting point, the aluminium lower section
holding the engine in position, the forged aluminium auxiliary frame serving
to take up spring strut forces, and the aluminium frame bolted on at the rear.
With its appropriate use of materials specifically chosen at
each point and tailored precisely to load requirements, this concept makes a
significant contribution to the minimisation of overall weight – which is
precisely why the various models weigh a mere 156 kg/344 lb (Xchallenge, the
lightest
model) to 160 kg/353 lb (Xcountry, the heaviest model) with a full tank
according to the DIN standard.
The intelligent mix of materials on the frame
offers a
number of other benefits: The aluminium castings around the swing arm
mounting
point the rider is bound to touch with his boots are eloxy-plated to
prevent
any such contact from leaving behind unwanted marks. At the same time
the swing
arm mounting point has been modified in its configuration, the swing
arm now
pivoting exclusively on the main frame and not on the engine block, and
being positioned relatively close to the pinion. This not only serves
to
provide even faster drivetrain response, but also reduces the tolerance
(less slackness) of the drive chain.
Light rear frame and lower section made of aluminium.
The rear frame is bolted on to the main frame, allowing easy
and low-cost replacement in the event of damage. To make the rear frame
resistant to even the highest loads, high-strength aluminium forgings are
welded into the ends of the eloxy-plated aluminium frame tubes bolted on to the main frame. The
lower frame section holding the power unit at the front boasts the same very
special lightweight technology.
Double swing arm made of cast light alloy.
The extremely stable, double aluminium swing arm also comes
with top-quality eloxy-plated surface finish. Made of cast aluminium, the
double swing arm is heat-treated in the production process in the interest of
even greater strength and stability provided by the more consistent grain
structure of the material.
Wheel guidance on all models in the BMW G 650 X range is
provided by a spring strut pivoting at the top on a forged aluminium mount. This ensures
smooth and consistent distribution and flow of forces, since the forged
aluminium support rests itself on two points – first, on the side sections of
the frame, and second, on the cylinder head itself through a bolted connection
and, in the immediate vicinity, on the stable connection linking the cylinder
head and the frame of the motorcycle.
Upside-down telescopic fork with different spring travel on each model.
The upside-down telescopic fork (USD fork) is one of the
suspension components identical on all three models in the new BMW G
650 X
model range. The different character of each model is borne out by
different spring travel, a different set-up, and differences in design
and configuration
around the wheel mounting point. A further feature on the Xmoto and
Xchallenge
is adjustment of the telescopic fork both inbound and outbound.
With tube diameter of 45 millimetres or 1.77´´, forged
aluminium fork bridges, and wheel axle diameter of 20 millimetres or 0.79´´,
the telescopic fork is extremely strong and torsionally resistant, ensuring supreme directional
stability at all times.
Tank fitted in the frame triangle for optimum weight
distribution and concentration of masses.
The position of the fuel tank in the frame triangle beneath
the seat, a concept already proven on the F 650 GS, has been carried over to
all three single-cylinder models on account of its obvious benefits, with optimum
concentration of masses near the motorcycle’s low centre of gravity.
Made of a special plastic material, the fuel tank has a
capacity of 9.5 litres or 2.1 imp gals and is filled from the right through the lockable tank filler
pipe. Even though this fuel capacity may appear to be relatively small at first
sight,
it is sufficient for a cruising range of up to 250 kilometres or 155 miles,
since the single-cylinder power unit is very fuel-efficient.
Light and modern two-channel ABS – quite unique in this
segment.
As an option, the G 650 X models are available straight from
the plant with new two-channel ABS from Bosch, the latest generation of BMW Motorrad ABS
already featured on the F 800 S/ST and the R 1200 S. The particular advantages
of this anti-lock brake system are not only compact dimensions and low weight
of just 1.5 kg or 3.3 lb, but also a high standard of precision and quality in
controlling the brakes: The pressure modulator masterminds optimum brake
pressure in the ABS mode via intake valves with linear control, keeping the
control intervals very fast and precise. And a further advantage
of the modern valves with their infinitely variable cross-sections is that the
rider feels only a very weak pulse effect in the brake levers.
Enhanced diagnostic functions round off the benefits offered
by this modern and sophisticated ABS control system. The wheel speed sensors,
for example, automatically monitor their distance from the sensor wheel and
thus contribute to the supreme standard of safety offered by the system. To ensure
an optimum and consistent pressure point at all times, the brake system comes
with steel-reinforced brake lines even on models not fitted with ABS.
A further point is that the rider is able to deactivate the
ABS anti-lock brake system when riding offroad under particularly sporting
conditions or when enjoying his machine on a closed circuit. And last but not least,
all models fitted with ABS come complete with a 12-V power socket.
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