BMW's new range of 650 singles

Reflecting the different sporting requirements and demands made of each model, a number of components have been modified to reduce the weight of the new motorcycles by approximately 2 kg, enhancing the engine’s fast-revving response and performance and boosting engine output by 2 kW.

As a result, the power unit not only offers maximum output increased to 39 kW or 53 hp at 7,000 rpm and peak torque of 60 Nm or 44 lb-ft at 5,250 rpm, but also even more dynamic performance and a greater athletic character in every respect.

Even lighter than before, the alternator minimises the free mass weight of the entire crankdrive system running in anti-friction bearings, giving the single-cylinder even more spontaneous and athletic performance.

The balance shaft serving to optimise smoothness and running refinement has been retained, with the new starter and alternator cover made of magnesium making a significant contribution to the lower weight of the engine. The redesigned four-valve cylinder head, finally, serves mainly to connect the power unit ideally to the frame and suspension as a load-bearing element.

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.

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