The BMW Motorrad principle Safety 360: Suspension technology







Published by Gerald Ferreira Date: July 4, 2012
Categories: BMW, BMW Motorcycles, Motorcycles

Innovative suspension technology – a longstanding characteristic feature of BMW motorcycles.

BMW Motorcycles

The design of all chassis components has a major impact on traction, ride stability, agility and comfort. The ability to accelerate, steer or brake the motorcycle or scooter in all situations is imperative from the safety perspective – as well as being a crucial factor in terms of riding dynamics and riding fun, too.

Innovative chassis developments run through the almost 90-year history of BMW Motorcycle like a golden thread. The first hydraulically damped telescopic fork in a serial production motorcycle (1937), long swing arms (1950s and 1960s), long-stroke comfort telescopic forks (1970s), Paralever (1987) and Telelever (1993) remain milestones in motorcycle technology to this day, invented or refined and used in serial production for the first time by BMW Motorrad. Particularly notable innovations of the recent past are the electronically adjustable suspension systems.

Front suspension as a fundamental component of a motorcycle in terms of ride precision and ride comfort.

In the R 1100 RS presented in 1993, the power unit was designed as a load-bearing element for the first time in a BMW motorcycle, so there was no longer any frame in the conventional sense. Front wheel suspension uses the BMW Motorrad Telelever, a combination of triangular swinging arm and telescopic fork supported by the engine block. The benefits of this system are extremely sensitive response, torsional stiffness and braking stability.

Up until 2004, the Telelever was the only type of front-wheel suspension able to establish itself alongside the dominant telescopic fork: it offers superior properties in terms of function and comfort and was the optimum solution for motorcycles in the boxer twin series at the time.

The subsequent advancement came with the K 1200 S in 2004 and is still in use in BMW motorcycles today: the Duolever is an effective alternative to the Telelever in the BMW Motorrad 4-cylinder series. This type of front suspension also provides riders with sporty ambitions a sense of safe control in all situations in that it separates the functions of wheel control on the one hand and suspension/damping on the other. The benefits here are a high degree of stability and only slight suspension dive when the brakes are applied.

The BMW Motorrad Paralever as an innovative optimisation of rear wheel suspension in conjunction with cardan shaft drive.

In 1987 BMW Motorrad put the R 100 GS on the market – not just the highest capacity enduro but also one which featured an outstanding technical innovation in the area of rear wheel suspension: the double-pivot rear swinging arm BMW Motorrad Paralever. The Paralever uses torque bracing to eliminate unwanted drive torque generated by the cardan shaft drive such as righting moment and suspension hardening during acceleration. The effect clearly felt by the rider is a calmer, more stable and ultimately safer ride response.

Electronic Suspension Adjustment ESA.

The launch of the BMW K 1200 S in 2004 saw the first use of electronics in a serial production motorcycle chassis. Electronic Suspension Adjustment or ESA for short (an ex works option) allows the suspension to be adapted as preferred at the press of a button – for maximum convenience and even during travel. It was the first system in the world to comprise electronic suspension adjustment in motorcycles. The components adjusted are the spring mount and the rebound and compression stage of the damping.
On the front wheel only the rebound damping is varied.

Operation was designed to be as simple and comprehensible as possible. The rider simply chooses the load state ("solo", "solo with luggage" and "with passenger and luggage") and the damping level according to the intended riding style ("Comfort", "Normal", "Sport"). Spring mount adjustment is carried out by an electric motor with a hydraulic system. The damping rate is altered by means of small, light stepper motors at the damper.

As a result, the drive response of the K 1200 S is largely independent of the various load states and can be adapted by riders to their own personal needs – a significant increase in ride safety and comfort.

Enduro ESA for off-road use.

Designed for the specific requirements of a travel enduro bike, a new version of the ESA system presented in 2009 in the new R 1200 GS and R 1200 GS Adventure models likewise allows adjustment of the suspension: the Enduro ESA not differentiates between various load states and riding styles but also between on-road and off-road use – if necessary, ground clearance can be increased over two levels, for example.

ESA II – spring rate adjustable now too, alongside suspension/damping.

As an optional extra ex works, the rider of the successor model of the
K 1200 S – the K 1300 S – can conveniently press a button to adapt not only the damping properties of the front and rear spring struts and the spring mount ("spring preload") of the rear spring strut but also as the latter's spring rate and therefore the "hardness" of the suspension. This second generation Electronic Suspension Adjustment – or ESA II for short - allows a previously unheard of level of suspension adjustment to rider and load with the very highest level of operational convenience. The result is a new dimension of ride stability and outstanding responsiveness in all riding and load states, thereby providing an additional safety bonus especially when braking.

BMW Motorrad Dynamic Damping Control DDC – semiactive suspension technology for the future.

BMW Motorrad is permanently involved in refining suspension technology so as to be able to offer even more effective suspension/damping systems in the future for further enhanced riding dynamics and riding safety. One example of this is Dynamic Damping Control, or DDC for short. BMW Motorrad will be incorporating this system in the serial production of its vehicles in the near future

Dynamic Damping Control DDC goes one step further than the current ESA II system. The semiactive suspension system reacts automatically to manoeuvres such as braking, accelerating, and cornering on various road surfaces and analyses the situational parameters provided by sensors to set the correct level of damping at electrically actuated proportional EDC valves. Greater safety is the welcome outcome – especially on poor road surfaces.

Selected at the press of a button, three characteristic maps for the basic configurations “Comfort”, “Normal”, and “Sport” allow riders to realise their own preference on this system too. Like ESA II, DDC also allows the spring rate to be varied.

DDC is networked with the other BMW Motorrad control systems – ABS and DTC – via the CAN bus; the system detects any control activity in these other systems and adapts damping within milliseconds as needed.