THE 2010 BMW R 1200 RT: New Boxer Engine Brings New Innovations in Touring
Woodcliff Lake, NJ – November 5, 2009…The BMW R 1200 RT has always been acknowledged as the epitome of comfortable and dynamic motorcycle touring in classic style. And now, the latest version of this unique active tourer, with its significant innovations, offers even more superior enduro qualities and dynamic benefits thanks to its new boxer engine.
In its configuration and basic structure, the new flat-twin engine is the same as the Double Overhead Camshaft (DOHC) engine featured in the BMW HP2 Sport. It has, however, been
further upgraded and optimized for the BMW R 1200 RT to meet the specific requirements of an outstanding tourer.
With the 1,170-cc boxer engine on the former model already offering superior drive power under all conditions and in all situations, the new R 1200 RT has even more to offer. First, the new engine offers an increase in maximum torque from 85 - 88 lb-ft at an unchanged 6,000 rpm, for even greater acceleration and passing power. Second, the range of useful engine speed has been increased by 500 rpm to a maximum 8,500 rpm. The third improvement is a significant increase in torque where it really counts at low and medium engine speeds, with a smooth and homogeneous torque curve. Maximum engine horsepower is the same as the prior model at 110 hp but occurs now at 7,750 rpm (previously 7,500 rpm).
Overview of the main features of the 2010 R 1200 RT:
* New, even more dynamic engine with two overhead camshafts per cylinder
* Maximum torque increased to 88 lb-ft at 6,000 rpm, maximum output remaining at 110 hp at 7,750 rpm
* Increase in maximum engine speed from 8,000 to 8,500 rpm, with an even broader power band
* Significantly improved torque and acceleration
* Smoother Torque curve
* Cylinder head covers now with two, instead of four, fastening bolts and a new dynamic design
* Electronically controlled exhaust flap for superior and powerful sound
* ESA II Electronic Suspension Adjustment with damping, spring base and now also spring rate adjustable at the touch of a button
* BMW Motorrad Integral ABS featured as standard in the partly integrated version
* New design fairing with improved protection from wind and weather
* Re-designed cockpit with visor
* New control units and hydraulic reservoir
* Electronically controlled windshield with optimized aero-acoustics and improved transparency
New DOHC cylinder heads offer an even more efficient cylinder charge
Designed and built for even higher engine speeds, the R 1200 RT’s new boxer engine , like the engine featured on the BMW HP2 Sport, is equipped with two overhead chain-driven camshafts (DOHC) per cylinder. Valves are operated by very light rocker arms able to cope easily with high engine speeds. Radial arrangement of the four valves allows for a very compact combustion chamber configuration, and like that of the former models, the fuel/air mixture is ignited by two spark plugs (HP2 Sport: one spark plug). The compression ratio of 12.0:1 remains unchanged.
Knock control allows the engine to run on 95-98 RON premium (plus) fuel. Under certain conditions the rider may experience a very small drop in torque and a slight increase in fuel consumption whenever knock control cuts in.
Horizontal arrangement of the camshafts in the direction of travel calls for two special technical features on the new flat-twin engine: Each camshaft controls one intake and one exhaust valve, and the cams are finished in conical shape due to the radial arrangement of the valves. In the interest of power and performance at low and medium engine speeds, and to provide even better free-revving riding characteristics, the intake and exhaust valve timing on both camshafts has been further improved. Compared with the former models, the valve bases are up in diameter from 1.41 – 1.54 inches on the intake side and 1.22 – 1.30 inches on the exhaust side. Valve clearance is adjusted by light semi-hemispherical shims. To provide a greater free-valve cross-section, valve lift is up from 0.415 inches on the intake and 0.365 inches on the exhaust side to 0.425 inches on both sides.
Significantly more torque throughout the entire speed range
The existing ratio of bore to stroke remains the same at 3.98:2.87 inches, giving the engine the same 1,170 cc capacity as before. Other features borrowed from the former engine are the crankshaft and the connecting rods, as well as their bearings, while the two pistons made of cast aluminum have been re-designed to match the modified dimensions of the combustion chamber. Interacting with the upgraded intake system, throttle butterfly manifolds now offer 1.97 inches instead of the former 1.85 inches (HP2 Sport: 2.05 inches) opening clearance, newly designed intake air manifolds and an air filter element with increased volume capacity, the engine as in the past develops maximum output of 110 hp, now at 7,750 rpm. The biggest improvement, however, is the increase in maximum torque to 88 lb-ft at 6,000 rpm.
An oil cooler ensures a stable temperature even under extreme riding conditions. A further enhancement on the 2010 model is the use of cylinder head covers with two, instead of formerly four, fastening bolts in a new dynamic design. A valve cover guard made either of aluminum or plastic as well as chrome-plated aluminum cylinder covers are available as accessory items.
Electronically controlled exhaust flap for a superior muscular sound
On the exhaust system the two manifolds come in the same design, length and diameter as on the former model, while the interference pipe has been modified to take into account the different vibration conditions on the exhaust manifold.
Featuring an exhaust flap controlled via an electric motor and opening/closing cables, the new BMW R 1200 RT offers a particularly powerful boxer sound in full compliance with all legal standards. To reduce ram pressure and improve the sound of the engine, the rear silencer is unchanged in its exterior design versus the former models, but has a modified interior structure.
Ideal transmission of power thanks to six-speed gearbox and drive shaft
As in the past, power is transmitted through the six-speed gearbox already upgraded in the 2008 model year, with larger bearing diameters and a modified gap between shafts. The maintenance-free drive shaft to the rear wheel is unchanged.
Suspension with Telelever and Paralever follows a proven principle at BMW
The proven, two-piece main/rear frame sections made of weight-saving steel tubes, incorporating the engine as a load-bearing element, offer maximum strength and stiffness under all riding conditions. The front and rear frame are firmly bolted to the engine/gearbox unit, interacting with the engine and gearbox to form a load-bearing structure. The longitudinal arm on the front Telelever suspension is mounted as before on the engine block, while the Paralever swing arm is attached to the rear frame.
With its fixed tube measuring 1.38 inches in diameter, the Telelever is the optimum solution for the rider using his machine exclusively on the road and focusing in particular on superior comfort. This is ensured by an optimal balance of sporting and comfort-oriented suspension behavior, the maintenance-free system once again designed to reduce brake dive to almost zero, which helps to provide greater stability when applying the brakes particularly when leaning over at an angle.
As in the past the Paralever swing arm in the rear central spring strut offers travel-dependent damping or TDD for short, with the damping effect increasing progressively as a function of spring travel. This keeps the suspension smooth, sensitive and comfortable in absorbing even the smallest bumps, while at the same time offering generous reserves on bad roads with grooves or bumps and potholes.
As in the past, spring travel is 4.72 inches up front and 5.31 inches at the rear. In standard trim, the rear spring strut offers infinitely variable adjustment on the outbound stroke as well as a hand-wheel for infinitely adjusting the spring base by 0.39 inches to adjust the rear end to varying load requirements.
Like its predecessor, the 2010 BMW R 1200 RT rests on light, almost filigree cast aluminum wheels in five-spoke design, combining an attractive look with an easy-to-clean surface and a high standard of stiffness. The front wheel measures 3.5 x 17 inches, the rear wheel 5.5 x 17 inches, running on a 120/70 ZR17 tire up front and a 180/55 ZR17 tire at the rear.
ESA II Electronic Suspension Adjustment offers adjustable damping, spring base and now also spring rate
The BMW R 1200 RT is available with ESA II (Electronic Suspension Adjustment II) already well-known from the K series as an option at extra cost. Benefiting from this unique system in the world motorcycle market, the rider is able to adjust not only the damping on the outbound stroke of the front and rear spring strut, but also the spring base (spring pre-tension) on the front spring strut and the spring rate – all at the simple touch of a button. This second-generation Electronic Suspension Adjustment or ESA II for short provides the option to set the suspension for maximum comfort and, with greater precision than ever before, for optimum riding and load conditions. It ensures a new dimension of riding stability combined with premium response.
To control the Electronic Suspension Adjustment as easily as possible and to prevent any unwanted settings, the rider initially enters the motorcycle’s current load condition (solo, solo with luggage, rider with passenger and luggage). The appropriate spring base and spring rate is then set automatically, with the system coordinating these two parameters to one another.
Depending on the style of riding he wishes to enjoy, the rider must also choose among the Comfort, Normal or Sport mode, giving the suspension the desired qualities. Applying the optimum parameters in the Central Vehicle Electronics, the electronic “brain” calculates the appropriate damper rates and sets them accordingly. As a result, the new R 1200 RT benefits from a total of no less than nine different set-up options.
With additional adjustment of the spring rate, ride height can be set to various load conditions, ensuring an even higher standard of riding stability, handling and comfort. Even when carrying high loads with a passenger and considerable luggage, the R 1200 RT maintains all of its riding qualities when leaning over at a low angle in turns for a truly sporting style of ridin.
A further advantage is that adjustment of the spring rate dramatically reduces the risk of the suspension suddenly sagging under extreme load. The rider is able to change the damper setting (Normal, Sport, Comfort) simply by pressing a button while riding, although for function and safety reasons the spring base may be changed only at a standstill. The spring rate is adjusted by an electric motor complete with its own transmission, while the damping rate is modified by small step motors on the dampers.
Adjustment of the spring rate is controlled by two springs connected in a series, one behind the other. An elastomer unit (Cellasto) in combination with a conventional coil spring takes up forces under spring pressure, while radial expansion of the Cellasto element to the outside is restricted by a steel sleeve. On the inside, the Cellasto element moves an aluminum sleeve by means of electro-hydraulic connection. The position of this inner sleeve influences the expansion behavior of the Cellasto element to the inside and, therefore, its spring rate.
In all, this interaction of the various units has the same effect as a combination of two springs varying in strength. Whenever the inner sleeve is resting on the steel spring, the Cellasto unit is not in use and only the steel spring provides the desired suspension effect. Once the inner sleeve is moved further, the spring base on the steel spring – and therefore the spring pre-tension – is also varied accordingly.
This configuration significantly improves the normal static position of the motorcycle and riding geometry under all load conditions, without any of the disadvantages encountered with conventional suspension. Benefiting from this self-leveling capability, the R 1200 RT is just as stable when riding under full load as it is when carrying only the rider without any luggage.
Additional adjustment of the spring rate over the wide range from 118-192 ft /lb allows far greater variation of the Sport, Normal and Comfort settings on ESA II than on ESA I, with each set-up providing a far greater choice of specific characteristics.
In other words, the R 1200 RT is even more dynamic and precise in the Sport mode, and very comfortable in the Comfort mode, while maintaining excellent stability.
In all, ESA II offers the following significant benefits:
* Much wider range of settings and suspension options with the Sport, Normal and Comfort modes
* Far better maintenance of the machine’s static, normal position and riding geometry with all settings
* Optimum adjustment of the damping and spring rate / spring base in all settings
* Significant change of the motorcycle’s character through adjustment of the dampers
* Excellent adjustment to all load conditions through the adjustment of the spring rate / spring base
* Significant enhancement of safety when braking and in general riding stability, free side angle in turns and firm suspension without sagging
(more later)