BMW Automated Shift Assistant
BMW’s new Automated Shift Assistant features two electromechanical actuators that automate the clutch and gearshift of the six-speed transmission.
There is no need for a hand lever to operate the clutch manually.
In 2007, Yamaha introduced a similar system to their FJR1300 sports-tourer. Both the Yamaha, and the new BMW solutions, are very different to Honda’s much more sophisticated but heavier and bulkier DCT gearbox.
BMW claim their Automated Shift Assistant offers fast, rev- and load-adapted shift sequences, which result in precise gear changes.
In ‘M’ shift mode, gear changes can still be made by foot control, allowing the rider to decide when to change gears.
In ‘D’ shift mode, shift points are automatically selected by the engine control unit.
In both “M” and “D” modes, BMW claims that riders benefit from perfectly executed gear changes which results in more efficient motorcycle acceleration and increased riding stability.
Specific characteristics of the automated shift function are assigned to the different riding modes.
Two electronically controlled electromechanical actuators operate the clutch and gearshift, enabling easy starting and automated gear changes.
The rider’s shift request is transmitted to the control unit via a gearshift lever sensor, which is actuated by the conventional foot-operated gearshift lever.
Additional sensors determine the revs of the transmission input shaft and the clutch position.
These values are transmitted to the TCU (Transmission Control Unit), which is closely linked to the engine control unit, for modelling and control of the clutch, shift actuation and status.
The clutch is operated by an electro-mechanical actuator combined with a hydraulic system with a direct hydraulic connection between the clutch master and slave cylinders. The actuator regulates the required clutch slip, engages the clutch when changing gear and disengages it when stopping.
In manual shift mode “M”, the rider can move the gearshift lever in the desired direction in the usual way. If the revs in the desired target gear are within the maximum or minimum rev range, the shift is made directly. If the engine revs fall below a gear-dependent minimum speed, downshifts are also performed automatically in manual mode. This prevents the engine from stalling.
In shift mode “D” the gears are changed automatically depending on the riding mode, engine revs, throttle position and lean angle parameters. Gears are shifted according to the riding situation and dynamic requirements.
It appears that this system will first be offered on BMW Boxer models.
This will be an appealing feature for some riders, those that are well-aged/infirm to keep them riding, and also, of course, for those of us with hand/ankle/foot injuries where this could make life easier. But what we really want is a MotoGP seamless-shift box…
