The new BMW R 1200 GS and the new R 1200 GS Adventure, BMW Motorrad is opening up yet another chapter in the story of highly successful GS models which, for almost three decades, have been the epitome of the large-capacity grand touring enduro. Moving on from the former generation of the R 1200 GS and R 1200 GS Adventure, which already offered supreme power and performance as well as a very broad range of practical riding qualities for long tours combined with supreme pleasure on winding country and mountain roads, BMW Motorrad is now enhancing this standard, as impressive as it already is, to an even higher level.

Intake and exhaust timing on the two camshafts has been optimised in particular for supreme power at low and medium engine speeds and for even faster, free-revving engine performance throughout the entire range. To increase the free valve cross-section, valve lift is up by 10.54 mm (0.415″) on the intake and 9.26 mm (0.365″) on the exhaust side to 10.8 mm (0.425″) on both sides. Valve clearance is compensated by light semi-hemispherical shims.

The existing ratio of bore and stroke of 101:73 millimetres (3.98 : 2.87″) remains the same as before, as does the engine’s cubic capacity of 1,170 cc. Other features likewise carried over from the former power unit are the crankshafts and connecting rods as well as their mounts and bearings, while the two new cast-aluminium pistons have been re-designed to match the change in combustion chamber geometry.

Interacting with the upgraded intake system now featuring black instead of silver throttle butterfly manifolds as on the former models measuring 50 mm (1.97″) instead of formerly 47 mm (1.85″) (HP2 Sport: 52 mm/2.05″) opening clearance and with newly designed intake air funnels and an air filter element with higher throughput, the engine now develops maximum output of 81 kW/110 PS at 7,750 rpm and peak torque of 120 Nm/88 lb-ft at 6,000 rpm. An oil cooler ensures stable thermal conditions even when riding to the extreme.

In all, the modifications to the drivetrain provide a significantly more homogeneous flow of power and torque throughout the entire speed range. In this process of technical development, the engines now feature magnesium-coloured cylinder head covers with two instead of formerly four fastening bolts and come in new, even more dynamic design. A valve cover guard made of aluminium or plastic as well as a chrome-plated aluminium cylinder head cover may be retrofitted as special equipment.

Featuring an exhaust flap controlled by an electric motor as well as opening and closing cables, both the new BMW R 1200 GS and the new R 1200 GS Adventure provide a particularly throaty boxer sound naturally in full compliance with legal standards. And to reduce ram pressure and improve the sound of the engine even further, the rear silencer remaining the same in design as on the former models comes with a completely new interior structure. Ideal transmission of power through six-speed gearbox and drive shaft.

Power is transmitted as before by the proven six-speed gearbox with larger bearing diameters and a modified distance between the individual shafts already upgraded technically for the 2008 model year. In the process the gear ratios were once again adjusted and the secondary transmission has been modified from i = 2.82 to i = 2.91.

Like their predecessors, the new R 1200 GS and R 1200 GS Adventure offer an almost perfect synthesis of offroad and onroad riding qualities. As in the past, the stiff and torsionally-resistant suspension, front wheel guidance with the unique BMW Telelever, and the rear wheel incorporating the BMW Paralever guarantee first-class and absolutely safe riding qualities also with the new engine offering even more power and torque. In conjunction with optional BMW Motorrad Integral ABS, extremely powerful brakes serve additionally to provide maximum safety even in critical situations. Optimum environmental compatibility, finally, is ensured also on the new boxer engine through the most advanced exhaust gas management with a fully-controlled three-way catalytic converter.

Designed and built for the specific requirements of a grand touring enduro, Enduro ESA Electronic Suspension Adjustment available also on the latest version of the R 1200 GS and R 1200 GS Adventure as an optional extra straight from the factory allows adjustment of the running gear under all kinds of running conditions and with virtually any load level, simply by pressing a button. An important feature is that Enduro ESA offers both an onroad and offroad mode within which the rider, choosing specific settings for the spring base and damping, is able to adjust the suspension even more precisely to specific needs and requirements.

Made of a heat-treated aluminium tube, the high-quality and sophisticated handlebar, interacting with two asymmetrically mounted clamps turning by up to 180o, as on the HP2 Enduro Sports, may be fitted in two ergonomically different positions. While the rear handlebar position for riding onroad and in less demanding terrain ensures optimum ergonomics particularly for the shorter rider, the front handlebar position offers advantages in particular when standing up on the machine in rough terrain.

The hand protectors available as special equipment for the R 1200 GS are fitted as standard straight from the factory on the R 1200 GS Adventure. In the process of technically upgrading the successful R 1200 GS models, the instrument cluster has received a new dial in new design. And last but not least, the windshield now comes with larger hand-bolts with even better grip for adjusting its position with greater ease.

As a genuine, fully-fledged systems supplier, BMW Motorrad has developed a wide range of optional extras and special equipment for further customisation of the new R 1200 GS and R 1200 GS Adventure. One particularly important new feature is the additional headlights in LED technology. Optional extras come directly from the factory and are fitted during production at the Berlin Plant, accessories and special equipment are fitted subsequently by the BMW Motorcycle Dealer.

Review

Just when you thought that BMW’s venerable flat-Twin had reached the logical conclusion of its evolution with the R1200′s cam-in-head design, the Germans go and throw us a wonderful curveball. The first pitch was the dohc setup that debuted in 2007 on the limited-production (and expensive) HP2 Sport. We never thought those exotic parts would ever find their way to the rest of the Boxer lineup, but here they are!

Whether the present R1200GS, R1200GS Adventure and R1200RT flat-Twins needed dohc in place of successful and elegant cam-in-head setup is one of those questions that probably won’t ever be answered by the project engineers. They wanted it, they were able to do it, so they did it. And it is also likely that all Boxers will get this engine in due time. The main challenge in applying dohc to this mill has been that, if a traditional design were used, the cam chains would get in the way of either the inlet or exhaust ports. In the 1950s, BMW solved that issue with a race-only version of the R50, a 500cc Boxer Twin featuring bevel-gear-driven dohc heads, very much in Norton Manx style.

Bevel-driven cams are fine on a racer, but chains are much more cost-effective and practical. So, to maintain the traditional longitudinal Boxer port arrangement with exhausts at front and intakes at rear, BMW developed camshafts carrying one inlet and one exhaust cam lobe each, rather than the more traditional setup grouping intake lobes on one cam and exhaust lobes on the other. To set the opposed inlet/exhaust valves at the proper included angle, the lobes are conically ground and actuate the valves through suitably inclined finger-type cam followers. This arrangement also allows a relatively small radial included valve angle of 22 degrees that yields a very compact and tidy combustion-chamber profile.

Benefits were plain on the HP2 Sport. That engine allegedly made 128 horsepower, a significant bump from the cam-in-head R1200S and its claimed 122 hp, with more power through the whole rev range.