BMW's air-cooled boxer twin-cylinder engine is on the ropes and fighting for its life as a long battle with Europe's increasingly-stringent emission laws enters its final round.
Motorcycles will have to meet Euro 4 standards by 2014, and the step up from Euro 3 is quite a challenge given that it requires a healthy 25 per cent reduction in toxic exhaust gas emissions.
Click photo at left for more views of the BMW R1200RT.
Will Euro 4 sound the death knell for the air-cooled motorcycle engine? BMW obviously thinks so judging by all the spy shots that are now circulating of new liquid-cooled boxer twin-powered prototypes.
AT A GLANCE
Engine: 1170cc air-cooled dohc 8v boxer twin stoked by fuel injection to develop 81kW (110bhp) at 7750rpm and 120Nm of torque at 6000rpm.
Transmission: six-speed sequential gearbox, shaft final drive.
Frame: What frame? Engine used to connect alloy telelever and steel-tube rear monoshock sub-frames together, both of which feature sophisticated electronic suspension adjustment on this model.
Hot: Still a punchy and dynamic bike to ride despite the wealth of fitted equipment; last of the air-cooled boxer engines delivers character and punch in equal measures.
Not: Just one equipment level on sale in New Zealand, a market that has no entry-level version priced in the low-thirties.
So the 2012 R1200RT you see on this page could be the last of a long line of fully dressed air-cooled touring bikes from the Bavarian brand, and the last that's able to trace a direct mechanical relationship to the original land-bound Beemer - the air-cooled R32 boxer twin of 1923.
There's a certain irony evident in BMW's projected shifting of the boxer twin engine from air-cooling to a water pump and radiator.
Horizontally opposed engine formats, whether selected to power the original Volkswagen, first Porsche 911, or even better, a motorcycle, are useful mainly for their ability to stick the architecture that needs cooling most out in the oncoming breeze. Certainly this was the quality that inspired the brilliant British aeronautical engineer, Granville Bradshaw, to build a boxer twin engine for his first motorcycle, the Sopwith-powered ABC 400 of 1919. Recently-defeated German engineer, Max Friz, designer of the most powerful aircraft engines of WW1, then used Bradshaw's bike as more than inspiration for the R32.
The first land-based BMW was virtually a carbon-copy of the ABC that preceded it, and Friz flirted with the boundaries of blatant plagiarism simply because he recognised the boxer twin engine layout of the British bike made air-cooling more effective.
As a "final hurrah" for a trustworthy and much-revered family of air-cooled motorcycle engines, the R1200RT SE tested is about as good as such corporate gestures get. The air-cooled boxer will leave the sales arena next year not as some fat piece of obsolete tack, but in the fittest shape that it has ever been, with an ability to deliver its strongest punch ever. It may be older than Muhammad Ali, but the years have been considerably kinder to the machine than the man.
For the RT got a serious upgrade in 2010, gaining the new 110bhp "twin cam" air-cooled boxer twin shared with other R-series bikes, an even-more effective fairing design, and a number of detail changes that included the welcome pruning of the contentious three-button indicator controls to excellent single-button self-cancelling units.
In came a host of new equipment for the special edition version, including electronic suspension adjustment (ESA), cruise control, heaters for seats and handlebar grips, an audio system with Bluetooth connectivity, the best panniers in bikedom, power windscreen adjustment, tyre pressure monitoring system and traction-stability control. The $39,909 SE is the only R1200RT model on sale in New Zealand, so you have to accept the "kitchen sink included" fit-out of what is perhaps the best-equipped twin-cylinder touring bike on the market.
For some, further options like the $976 two-tone paint scheme of the test bike, and BMW's own $640 sat-nav system, will also be attractive, while total shopaholics will also spring for a pair of the brand's $1024 System 6 helmets as they're each tailormade to accept the neat $450 wireless communications system also on offer. This is definitely the most geek-friendly twin-cylinder tourer available.
Yet what makes the R1200RT SE so remarkable, is that it still handles and performs like a proper motorcycle beneath that rich and extravagant layer of standard equipment. The punchier boxer engine helps, as do the strong bite of the ABS brakes, the generous lean angles on offer when cornering, along with the sportier settings of the ESA-equipped suspension.
Price-point rival full dressers like Harley's Ultra Classic Electra-Glide are easily left wobbling and spluttering in the wake of the RT's passage down country roads here.
Finally, it is the rich character of the air-cooled boxer engine that leaves the lasting impression after riding the R1200RT. BMW's biggest challenge won't be meeting the new emission standard with the coming liquid-cooled replacement. It will be making sure that the boxer retains a soul.