Long-rumored, and preceded by spy photos, the switch to liquid cooling isn’t immediately evident on the new model. BMW is keen to emphasize its new Boxer as both air and liquid cooled. Indeed the Boxer heads protrude out, maybe even more prominently than before. More technical analysis of the liquid-cooling is forthcoming, for now we’ll let the BMW PR speak for itself, stating:
“The boxer engine in the new R 1200 GS continues to use air/liquid cooling, however, the coolant oil has been replaced by a glycol-water mixture. This ensures a high level of heat absorption capacity of the cooling liquid for more efficient heat dissipation.
“So-called precision cooling (a principle similar to that used in Formula 1) involves only those engine elements being cooled with coolant, which are particularly exposed to thermal stress. The engine still continues to use air cooling, thereby preserving the characteristic appearance of the opposed Twin boxer engine. The two radiators are small and inconspicuously integrated.”
The compact liquid-cooling system packs on weight, but only a claimed six pounds. Air-flow on the cooling fins on the exposed cylinder heads still do the lion’s share of temperature regulation. BMW claims the cooling ratio at 65% air to 35% liquid in the current model, with the previous version a ratio of 78% air to 22% oil.
As to the reasons for the move to liquid-cooling, BMW points to “preparation for the future in terms of noise and exhaust emissions.” The GS has also faced stern performance challenges in the AT class from the liquid-cooled Ducati Multistrada and Triumph Explorer, its two European rivals.
The new Boxer Twin looks to close the performance gap. Horsepower claims for the new GS jump up from 110 to 125 hp, the peak power coming at almost at the same 7700 rpm (7750 in previous version). Torque production climbs to 92.2 lb-ft at 6500 instead of 88.51 at 6000.
The 2013 R1200GS still keeps temperatures down primarily via air cooling, with BMW BMW claiming the cooling ratio at 65% air to 35% from the new liquid system.
The power gains come without an increase in its 1170cc displacement. The 101mm bore and 73mm stroke are unchanged as well. What has been revised is compression, up to 12.5:1 from 12.0:1 owing to a more compact combustion chamber. This comes courtesy of the new valve angles, intake positioned at eight degrees and exhaust at 10 degrees. (A new radial valve head was the signature upgrade to the 2010 Boxer models, including the GS.)
The GS remains shaft driven, with a six-speed gearbox. However, there are changes to the transmission system, as a wet clutch with “anti-hopping function” replaces the dry unit found on the predecessor.
A switch to ride-by-wire, dubbed E-gas in the BMW PR dialect, is a first for the GS, with a throttle sensor regulating the throttle valve via ECU. BMW hails improved throttle response and control. The electronic system also allows for cruise control and three selectable E-gas settings.
The new GS also premiers five ride mode options: Rain, Road, Dynamic, Enduro and Enduro Pro. These five modes feature “varying engine characteristics.” A special enduro configuration for the Automatic Stability Control (ASC) further varies the engine tune, with corresponding alteration of the five mode settings.
A redesigned chassis featured a new steel tube frame. BMW’s proprietary Telelever and Paralever suspension units return, though the Bavarians promise they are “newly designed.” The chassis revisions net claims of “further significant increase in torsional stiffness and hence ride stability and steering precision.” Claimed curb weight is 525 pounds, a 4.8 (4 kg) increase over the previous model.
The GS suspension package features BMW’s new semiactive Dynamic Electronic Suspension Adjustment (ESA). Beemer aficionados are familiar with ESA, with this latest Dynamic ESA incorporating spring travel sensors to automatically adjust damping via “electrically controlled regulation valves.” The new ESA adapts to the aforementioned ride mode settings.
New tire sizes get the GS rolling, a 120/70 front and 170/60 rear (previous model 110/80, 150/70).
The braking package upgrades with radial Brembo monobloc calipers up front. The rear two-piston caliper also pinches down on a now larger disc, up to 275mm from 265mm. BMW’s part integral ABS returns as a standard feature.
Remaining spec sheet prizes include an LED headlight with integrated daytime running light, with BMW claiming it as an industry first. The GS also benefits from innovations trickling down from the uber touring K1600GT six-cylinders, namely the improved electronics and a Multi-Controller switchgear – which allows for easy use of the BMW Motorrad Navigator IV instrumentation system. Another touring-oriented update is the new windshield, which allows for one-handed adjustment.
Ergonomic comfort is promised with a more adjustable seat. Previously able to alter the ride height between two settings, the new seat also offers adjustment for tilt angle. The passenger seat can also be repositioned.
The revitalized GS will be offered in four colorways: Alpine White, Racing Red, Blue Fire and Thunder Grey Metallic.