Duolever Tech

The sexy K1200R!

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MikeCam
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Duolever Tech

Post by MikeCam »

Recopied w/ permission/fair use...do not use for commercial purposes.

From BMW Motorrad...

Duolever
The BMW Motorrad Duolever front wheel suspension, which is fitted for the first time to the series production motorcycle K 1200 S, represents a revolutionary innovation in chassis technology. It sets new standards particularly in regards to comfort, braking stability, and handling. It is the first time a motorcycle has featured a double trailing link-front wheel suspension, built and patented by the British inventor Norman Hossack back in the '80s.

The Duolever front wheel suspension is kinematically regarded as a square joint, in which two trailing links made of forged steel are attached via rolling bearings to the frame. These trailing links, which visually resemble a conventional fork, guide the extremely torsionally rigid wheel carrier made of aluminium permanent mold casting. A central strut, which adjusts the suspension and damping, is linked to the lower of the two trailing links, and rests against the frame.

A trapezoidal shear joint mounted to the control head and the wheel carrier is coupled with the handlebar. This shear joint transmits the steering movements. Thus, the Duolever design in contrast to the telefork does not need sliding and fixed tubes. At the same time, it decouples the steering as well as the damping more consistently than the proven telelever. In the end the rider profits from a maximum of comfort and road grip, which have reached a yet unknown level, due to this decoupling of the steering and the suspension.

The advantage of this most innovative front wheel suspension on the motorcycle market at present is its torsional rigidity. The BMW Motorrad Duolever front wheel suspension is not influenced by negative forces in the same manner as a conventional telefork whose fixed and take-off tubes twist laterally as well as longitudinally during jounce/rebound and steering.
Its two trailing links absorb the forces resulting from the jounce/rebound and keep the wheel carrier stable. Thus, any torsioning is excluded and the front wheel suspension is very precise. The steering commands of the rider are converted directly and the feedback from the front wheel is transparent in all driving conditions.

A kinematical anti-dive effect is additionally achieved, just as for the Telelever, due to a well-aimed arrangement of the trailing link bearings. While a conventional telefork during strong braking manoeuvres jounces heavily or "locks", the Duolever still has sufficient spring travel remaining in this situation and therefore the rider can still brake into the corner extremely late yet directionally stable.

The obstacle-avoidance manoeuvre of the front wheel when riding over uneven surfaces can be converted with the Duolever similar to the behaviour of a telefork. In connection with the low unsprung masses and the small breakaway forces of the system, this results in more sensitive and comfortable response characteristics.

The K 1200 S and the K 1200 R with their BMW Motorrad Duolever front wheel suspension combine all the features regarded previously as opposite: Outstanding directional stability at high speeds, superior handling, precise steering sensation and directionally stable brake reaction in each speed range.

END

Now that's what I was trying to say all this time!
The Older I Get, The Less I Know.
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