Connectivity is evolving fast with e-mountainbikes, and automatic shifting is the latest hot trend. Now, motor colossus Bosch just jumped on the automatic shifting wagon and complemented their Smart System with the eMTB-specific eShift function. But how does it compare to the strong competition from Shimano and SRAM?
Although automatic shifting is nothing new in the eMTB segment, it hasn’t yet conquered the market. However, the race has begun: in 2022, component giant Shimano introduced their XT Di2 groupset with Autoshift function, and a year later, SRAM followed with their new Powertrain motor system with an integrated, automatic drivetrain. Now, Bosch have entered the game in the eMTB segment, offering a fully automatic shifting system for eMTBs and e-Gravel bikes with chain-driven drivetrains called the eShift. The German tech giant knows one or two things about electronic shifting, and introduced their first system back in 2014, enabling fully and semi-automatic shifting in urban settings. Alongside existing solutions for urban use, like the Rohloff 3X3 and Enviolo, there are now new drivetrains from Shimano (daily commuting) and TRP (eMTB) that are compatible with Bosch’s eShift function.
How Does Bosch eShift Automatic Shifting function work?
For MTB-specific applications, Bosch have teamed up with Taiwanese component colossus TRP. Bosch provide the software with the eShift function, while TRP supply the necessary hardware in the shape of the new electric, 12-speed E.A.S.I. A12 drivetrain. The latter draws its power directly from the bike’s main battery and has 520% gear range, matching existing solutions from SRAM and Shimano, which have the same gear range. In purely visual terms, the system ensures a clean cockpit. The wireless shifter is discreetly positioned on the right-hand side of the handlebar and communicates with the derailleur. The TRP groupset is only compatible with Bosch’s Performance Line CX and SX Smart System drives.
The software allows you to choose from different shifting functions, including shifting without pedaling and fully automatic shifting. In the fully automatic mode, the system selects the appropriate gear according to the riding situation using a shifting algorithm. By holding down the middle button on the Bosch Mini Remote, you can set the cadence between 40 and 120 RPM in increments of 5. For gear changes, the motor automatically turns the chainring – shifting happens automatically, both up and down. However, the system doesn’t change gears when stationary, as the motor only turns the chainring when the rear wheel moves.
You don’t want to give up control over shifting? No problem! While in automatic mode, you can shift manually too: pressing the shifter overrides the automatic mode and pauses it for a few seconds. This allows you to intervene at any time, for instance, when you unexpectedly hit a sharp turn or climb on the trail. Pressing the small button on the front of the shifter switches to manual mode, allowing you to take full control over the shifting process. The so-called roll-shift function, i.e., shifting without pedaling, is available too. Even if you stop, the system ensures a smooth transition when resuming your ride: an auto-downshift function shifts into a predefined gear when you come to a halt, making it easier to set off from a standstill. You can set your desired start-up gear using the Bosch eBike Flow app.
Like Shimano’s and SRAM’s automatic shifting systems, Bosch’s eShift function is fully integrated into the motor system’s software. The Kiox and Purion displays, as well as the Ride Screen on your smartphone, show which gear you’re currently using and whether you’re in manual or auto mode.
Jump in the saddle, Autoshift on? Bosch eShift on test
When you first swing your leg over the saddle, you won’t notice the difference to a Smart System bike without the eShift function. In manual mode, you change gears normally using the shifter, and the TRP drivetrain changes gears quickly and precisely. Gear changes under load are smooth, and there’s no annoying clunking noise when the chain moves across the cogs. The Roll-Shift function shows its strengths compared to a conventional drivetrain as soon as you hit a trail. Especially in technical sections with unexpected climbing sections, you can simply shift into the appropriate gear without smashing the cranks into rocks and roots. You can also shift into the right gear before a corner without having to pedal, which allows you to build up speed for a jump with just a few pedal strokes after a turn.
In automatic mode, Bosch eShift takes over the shifting. At first, it takes some getting used to the software taking control, the system often shifts in a moment you probably wouldn’t. With the Bosch Mini Remote, you can easily set the cadence you want the shifting algorithm to maintain, even while cruising along fire roads. This allows you to fine-tune the cadence, depending on whether you’re riding aggressively or more leisurely, on level ground or uphill. However, on trails, the Bosch eShift automatic function quickly reaches its limits. When approaching a steep climb, the shifting algorithm often doesn’t have enough time to shift into the appropriate gear. The software can’t “see ahead,” and only sends the shifting command when it’s too late, leaving you in a gear that’s too heavy for climbing. In this case, you can override the system with a manual shift command. Nevertheless, on trails with many climbs, you often find yourself working against the system, so we recommend deactivating Autoshift in these situations.
Autoshift is particularly suited for relaxed tours on moderate terrain. It allows you to focus entirely on riding without worrying about shifting. Especially when combined with the Bosch ABS system, which prevents the front wheel from locking up on loose surfaces, it makes for a safer, more fun riding experience for tour riders with little or no off-road experience.
How Does Bosch eShift Perform compare to Shimano Autoshift and SRAM Autoshift?
At first glance, all three systems aim to help the rider, but they only succeed to a limited extent, and the devil’s in the details. Unlike SRAM and Shimano, Bosch not only offer shifting functions but also additional features like the ABS system, delivering a solid overall package for off-road beginners and tour riders who prefer to take it easy on tours in moderate terrain. Compared to SRAM and Shimano, Bosch’s eShift Autoshift function shifts less frequently, which is more comfortable on tours, because the fewer gear changes ensure a more consistent cadence compared to other systems. In terms of haptic feedback, the TRP drivetrain of the Bosch system doesn’t quite match the Shimano and SRAM systems. Shimano offers a more premium feel for the same “analog” shifting experience. For those who prefer a fully digitalized shifter, SRAM’s PODs, which feel like buttons on a remote control, might be the solution, but they only work in combination with the Powertrain motor system. Unfortunately, if you want Bosch’s eShift function, you’re tied to TRP’s drivetrain and have to renounce SRAM’s popular shifting experience. The Roll-Shift function – shifting without pedaling – works equally well across all three systems and is a real advantage when negotiating technical terrain. With Autoshift enabled during sporty use on challenging trails, the systems from Bosch, Shimano, and SRAM all reach their limits quickly and are more suited for touring in moderate terrain.
Our conclusions about the Bosch eShift
Bosch are keeping pace with their eShift system, offering integrated automatic shifting for e-mountainbikes. Combined with other Bosch features like ABS, it provides a well-rounded package for improved safety and riding fun for off-road beginners in moderate terrain. However, on demanding trails, the automatic function quickly reaches its limits, just like its competitors. Sporty eMountainbikers will benefit more from the Roll-Shift function – shifting without pedaling.
Tops
- Shifting without pedaling
- Well-integrated shifting and motor system
- Automatic function helps off-road beginners in moderate terrain
Flops
- Autoshift reaches its limits in complex trail situations
- Shifter doesn’t feel as premium
For more information, visit bosch-ebike.com
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Words: Mike Hunger Photos: Mike Hunger
