Bosch is upgrading several of its e-bike motor systems via a free software update. Version 1.36 of the eBike Flow app introduces, among other features, a customizable Extended Boost mode and more precise responsiveness when pedaling—all without any new hardware.
Which motors are eligible
Bosch doesn’t just supply motors; it provides complete drive systems consisting of a motor, battery, display, and controller, which bicycle manufacturers then install as a package. The new update affects several of these systems: the Performance Line CX-R (BDU386Y), the Performance Line SX (BDU314Y), and the Cargo Line (BDU374Y). Anyone with one of these systems installed in their e-bike simply needs to update the eBike Flow app and the motor firmware.
Extended Boost Now Fully Adjustable
Until now, Extended Boost was a fixed feature. With the update, the duration of the extra boost can now be adjusted in several stages within the app. This allows the bike to continue moving for up to two meters even after the last pedal stroke—which is handy for clearing a root while mountain biking or a curb in the city. If you’re using this feature for the first time, proceed with caution and keep in mind that the drive system continues to provide a brief boost even after you stop pedaling.
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Pre-tensioned drivetrain for greater precision
A second innovation applies to the Performance Line CX-R (BDU386Y) and the Performance Line CX (BDU384Y9): In Race, eMTB, and eMTB+ modes, the drivetrain is now slightly pre-tensioned. This reduces pedal play and thereby shortens the motor’s response time. In practice, this should result in more precise, direct propulsion—especially on technical trail sections.
Free update without new hardware
Particularly convenient: Bosch is rolling out both features as a software-only update via the eBike Flow app; no hardware replacement is necessary. This update joins a series of previous eBike Flow updates through which Bosch has already added new features to existing systems on multiple occasions—such as automatic downshifting for Rohloff E-14 drivetrains or improved Komoot navigation.
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You can find out more about Bosch’s drive systems in our article on the Bosch Performance Line CX. If you’re still looking for the right bike, you’ll find what you’re looking for in our overview of the best e-bikes of 2025.
