Berlin, Germany - BMW has been building flat-twin ‘Boxer’ engines since 1923 and, despite a valiant attempt to replace them with a weird inline flat four in the 1980s, the horizontal pots sticking out on either side of the frame are still the marque’s defining feature.
But that doesn’t mean BMW Motorrad’s technology has stood still over the years, with dual overhead camshafts, four-valve heads, liquid cooling and electronic fuel injection replacing the erstwhile airheads, pushrods and Bing carburettors.
But now the Blue Propeller Boykies have taken that progress one huge step further with the R1250 GS beetle-crusher and RT full-dress tourer, incorporating new variable-cam technology on the inlet side for a wider, smoother spread of power. However, to keep up with significantly more powerful adventure tourers from KTM, Triumph and Yamaha they first bored the cylinders of the current R1200 out an extra 1.5mm and increased the stroke by 3mm to increase its displacement from 1170cc to 1254cc.
Then they fitted new four-valve heads with dual overhead camshafts driven by a quiet-running Hy-Vo toothed chain, rather than the previous roller chain. The inlet cams can also slide sideways, controlled by a helical groove that looks just like a miniature version of the shift drum in a constant-mesh gearbox, varying both the timing and the lift of the inlet valves for improved breathing and precise throttle control (fly-by-wire, of course) across the rev range.
More than that, one inlet valve opens a little ahead of the other, to induce a classic ‘twin swirl’ in the combustion chamber for cleaner, more efficient running, together with twin-jet injectors and a new exhaust system.
The result is a nine percent increase in power, from 92kW to 100kW at the same 7750 revs, and a 14 percent increase in torque, from 125Nm at 6250rpm to 143Nm at 6500rpm. BMW doesn’t quote performance figures but experience leads us to expect a noticeably sharper midrange, a broader powerband, quicker acceleration and a top speed of around 210km/h for the R1250 GS, perhaps a little more for the R1250 RT tourer.
Standard features on both R1250 models include two riding modes, automatic stability control and hill hold, with Riding Modes Pro, featuring more riding modes, dynamic traction control, and an entirely new dynamic brake assist system available as factory-fit options.
The RT tourer is now also available for the first time with ‘Next Generation’ dynamic electronic suspension adjustment, which automatically compensates for both load and road conditions, as well as the chosen drive mode, for the most stable ride response possible.
The RT has halogen headlights but the GelandeScooter comes with an LED headlight as standard and both R1250 models are available ex factory with LED daytime riding lights.
And finally, both models come with BMW’s multi-controller collar on the left-side switchgear, enabling access to both onboard and online functions. On the GS adventure tourer these are displayed on the bike’s 16.5cm full-colour instrument panel, while on the RT cruise liner they come up on a 14.5cm colour display mounted between the bike’s analog speedometer and rev counter.
The 2019 BMW R1250 GS and RT will be released in South Africa during the first quarter of 2019; prices, as always, when they get here.