Shifting without a lever

BMW launches automatic gearshift assistant for motorcycles

BMW dispenses with the clutch lever with ASA.

(Bild: markus-jahn.com)

Following in the footsteps of world market leader Honda, BMW now also has a motorcycle transmission in its range that takes over the clutch for the rider, but leaves the gearshift to the rider. For an authentic feel and "the emotionally important dynamics of the shifting process", according to BMW. Automated Shift Assistant (ASA) is what the brand calls its optional gear change alternative with fully automated clutch actuation, which was certainly not presented as an example in the top-selling BMW R 1300 GS by chance.

BMW's new transmission assistant is based on the company's own Shift Assistant Pro (clutch-free gear changes while riding) and basically merges two transmission role models: Honda's DCT dual-clutch transmission and the E-Clutch electronic clutch recently presented by the world's largest engine manufacturer. This means: engaging first gear, moving off, shifting up and down, stopping - all of this now works at BMW without having to pull the clutch, just like the new development from Honda. The left lever disappears.

(Bild: markus-jahn.com)

Unlike the Japanese, however, the Bavarians have thrown the clutch lever completely overboard. Instead, only a small button remains on the left-hand side of the handlebars. The rider uses this to decide whether he wants to change gears by foot ("M" for manual) or let the bike's electronics do all the shifting ("D" for drive). The automated shift assistant - just like Honda's DCT - can also change gears independently. The aim in both cases is to make riding more enjoyable - through fewer distractions and smoother gear changes.

(Bild: markus-jahn.com)

"Optimally selected gear changes create a new driving sensation with a more intense driving experience," promises BMW for the algorithm in "D" mode. Whether on a straight road, winding passages or in the city: the individual desire for propulsion is "always automatically assigned to the right gear, which leads to harmonious and extremely smooth driving behavior according to the driving mode".

One of the prerequisites for this is a six-axis sensor measuring unit (IMU), which almost all premium bikes have nowadays. The IMU constantly analyzes factors such as acceleration, speed and lean angle and adjusts ABS, traction control and, in this case, gear changes accordingly. On the road and off-road. The 145 hp boxer engine of the GS - "but also any other powerful engine from BMW Motorrad", says Product Manager Reiner Fings - harmonizes perfectly with the automated shift assistant, according to the first impression at the preliminary presentation in Enduro Park Hechlingen.

The ASA scheme

(Bild: BMW)

Although we were not yet able to ride the ASA-GS there ourselves, we expect to do so in the second half of 2024. The additional weight of the technology mounted inconspicuously under the bike is only 2.1 kilograms. This makes the new ASA transmission about as heavy as the already available Honda E-Clutch and, according to initial statements from BMW, about as expensive as the competitor's DCT, but saves the additional technical effort and weight of a dual-clutch transmission, which in the case of a Honda is around eleven kilograms. The new shift assistant, which undoubtedly takes motorcycling into a new era, will cost a little more than 1000 euros extra.

How the system works
Starting off is a breeze with the E-Clutch. Gear changes are smooth and fast. Annoying load changes and the jolt when shifting up with a manual gearbox are almost completely eliminated. BMW now promises the same.

The way the ASA works is reminiscent of a sequential car gearbox, explains Reiner Fings, Product Manager at BMW Motorrad: "Two electronically controlled electromechanical actuators operate the clutch and the gearshift, enabling easy starting and automated gear changes. The rider's shift request is transmitted to the control unit via a shift lever sensor, which is actuated by the conventional foot-operated shift lever. Additional sensors determine the speed of the transmission input shaft and the clutch position. These values are transmitted to the TCU control unit, which is closely networked with the engine control unit. The actuator regulates the required clutch slip, actuates the clutch during gear changes and opens it when stopping."

Sounds complex, but it works automatically on the motorcycle: The rider doesn't notice any of this. He simply accelerates and concentrates on riding and braking.

Only Honda has a DCT
It will probably only be a matter of time before other manufacturers jump on the bandwagon. For the time being, BMW wants to reserve ASA for more powerful machines in the upper displacement segment. Honda is different: the new electronic clutch will first be available in the mid-range CB650R and CBR650R bikes. Other models will follow. Unlike the DCT, the rider must always shift up or down by foot. As before, there is a clutch lever on the left-hand side of the handlebar. The rider can use this. Or they can leave it.

A coordinated combination of half actuation of the clutch and interruption of the fuel injection and ignition control prevents jolts when changing gear. The result is exceptionally smooth handling. Even when stationary, the driver can easily change through all gears - and even start off in a high gear without the risk of stalling if the downshift is forgotten before stopping at a traffic light. Similar to the DCT and ASA from BMW Motorrad, the clutch itself is controlled via an actuator unit, which in this case is located on the right-hand side of the engine together with two small electric servomotors.

If the rider pulls the clutch lever from time to time, the Honda E-Clutch is automatically reactivated after a few seconds. Alternatively, it can also be deactivated for an entire ride via the TFT display and the gears can be changed manually using a trigger gearshift with plus and minus buttons on the left-hand side of the handlebars. A feature for gearshift nostalgics, one might think, which is likely to have a similar career at Honda as DCT.

Honda e-Clutch

(Bild: Honda)

In 2010, the Japanese company launched the first and still only mass-produced dual-clutch transmission for motorcycles. The concept has been well received: Honda now only offers its Gold Wing luxury tourer, for example, which weighs at least 367 kilograms, with an automated 7-speed transmission. In the successful CRF 1100 L Africa Twin touring enduro, DCT (six gears) accounts for more than 55 percent, and more than half of customers also opt for assisted shifting on the NT 1100 sports tourer. Honda produces models such as the X-ADV SUV scooter and the Forza 750 scooter exclusively with DCT instead of the continuously variable CVT transmission commonly used on scooters.

"The best thing about DCT is that this technology frees up my mind to concentrate on the best thing about riding a motorcycle: Cornering, feeling the perfect line and timing when braking and accelerating," says Honda's DCT chief engineer Dai Arai. For those who are happy to do without the clutch, the E-Clutch is the perfect solution: it costs a mere 400 euros extra. (cen)