Autonomous Gear Shifting on Motorcycles: Experiencing Electric Mountain Bikes with Automatic Transmission on Public Roads
Bosch's Revolutionary eShift Technology Debuts in E-Bikes
Bosch, a leading delegate in the e-bike market, has introduced eShift technology, an electronic shifting system designed to enhance comfort and safety for e-bike users. First unveiled in 2015, the technology is aimed at streamlining e-bike systems [3].
The eShift system does away with the need for manual cable adjustments, replacing them with electronic signals for smooth and precise shifting. This feature reduces the cyclist's effort while ensuring a more convenient riding experience, particularly in dynamic conditions.
Integrated with internal hub gear drivetrains, the system enhances efficiency by adjusting gears automatically to the rider's requirements, such as adjusting for terrain changes. Additionally, the system supports Auto Shift technology, allowing gears to adjust based on riding conditions such as speed and terrain [2].
KTM Fahrrad's KTM Macina Kapoho Master ABS, the first e-bike model to feature eShift, is designed for a broad target audience. The automatic shifting function is intended for customers seeking even more focus on the trail and catering to both purists and riders who appreciate comfort-focused riding [1].
The KTM Macina Kapoho Master ABS boasts a removable and lockable drive battery, integrated into the carbon frame's down tube, providing an 800 watt-hours energy supply. On relatively flat terrain, the bike is capable of covering approximately 120 kilometers, even in cool temperatures. The full-suspension design, complemented by a Fox fork and rear shock with 160mm of travel each, enhances comfort and traction [1].
A Bosch Performance Line CX motor provides propulsion, offering a maximum torque of 85 Nm and an output of up to 600 watts [1]. The motor's continuous power output does not surpass the legally prescribed 250 watts. The battery also powers the automatic shifting system.
The eShift system analyzes various sensor signals to predict the driver's shifting preference. Crucial factors such as speed, driver torque at the crank, and cadence, which can be preset via the control unit and display or a Bosch app to an individually preferred RPM, are important considerations.
In practice, the eShift system maintains the cadence within tolerance ranges regardless of speed. However, it sometimes shifts unexpectedly for the rider, for instance, when more pressure is applied to the crank [1]. In such cases, gear changes are suppressed, says Tamara Winograd, head of marketing and communication at Bosch eBike Systems [1].
In dynamic riding situations, the chain of the 12-speed derailleur may switch abruptly to the adjacent sprocket, but the algorithm is designed to preserve the sprocket and chain, potentially extending their lifespan [1]. A planned software update aims to further optimize shifting behavior in challenging situations [1].
The system may struggle to react on steep inclines, necessitating manual intervention via the gear lever on the right handlebar [1]. E-Shift is more effective in situations that don't necessitate quick shifting.
The technology currently operates situationally and reactively. In the future, data on gradient, terrain, and vehicle dynamics could be employed to further tailor the shifting performance [1].
The KTM Macina Kapoho Master ABS offers additional features, including hydraulic disc brakes from Magura, MTB-standard four pistons, large brake discs, and an Anti-lock Braking System (ABS). A "ConnectModule" is installed, featuring GPS technology with a SIM card and motion sensors. This module, paired with a subscription for the first 12 months, allows the location of the bicycle to be determined via an app, and a theft alarm can be activated [1].
The eShift-equipped KTM Macina Kapoho Master ABS retails for 7,399 euros, a price deemed substantial. Bosch anticipates scaling effects, suggesting that eShift could also be available on e-bikes priced between 3,000 and 3,500 euros in the future [1].
While the eShift technology might seem underdeveloped and prematurely launched for the mountain bike segment, Bosch justifies the step and the development of the technology initially on the mountain bike. According to Winograd, "We want to be active where the demands are particularly high. If we achieve the best possible performance here, other segments will also benefit" [1].
As a result, eShift delivers notable comfort and is expected to redefine the e-bike market in the long run. Until then, cyclists can continue reflecting on the benefits of manual shifting.
The introduction of Bosch's eShift technology in e-bikes signifies an integration of technology and lifestyle, aiming to transform riding experiences through automated and efficient gear shifting. The upcoming scaling of eShift on e-bikes priced moderately amplifies the technology's potential impact on the sports industry, particularly the e-bike market.
