Bosch has released eBike Flow app version 1.36, adding more trail-side control for riders using the smart system. The update brings Extended Boost management into the app, introduces a Drivetrain Tensioner function and expands eShift with multi-gear changes, alongside a new eBike Assistant.
For UK eMTB riders, the most relevant change is not a headline increase in motor power. It is the ability to tailor how existing assistance behaves and to manage more of the bike’s connected functions from one place. Bosch says the update is available through the eBike Flow app version 1.36 release.
Extended Boost moves into the Flow app
Extended Boost is designed for short, technical moments when a rider needs assistance to continue after a deliberate pedal input. On steep steps, ledges or awkward root sections, that extra continuation can help maintain momentum without requiring a frantic extra pedal stroke in a vulnerable position.
Version 1.36 lets compatible riders manage Extended Boost in the Flow app. That makes the setting easier to find and adjust, although the available controls still depend on the motor, software and bike configuration. Riders should check compatibility in the app rather than assuming every Bosch smart-system eMTB receives the same options.
What Drivetrain Tensioner is intended to do
Bosch describes Drivetrain Tensioner as a way of improving how rider input is converted into propulsion. In practical terms, it is another example of the smart system using software to coordinate the drive unit and compatible transmission more closely.
The feature should not be confused with the physical clutch or cage tension in a rear derailleur. It is a system-level function, and its benefit will depend on the compatible drivetrain fitted to the bike. Owners should use the compatibility information shown in the Flow app and their bike manufacturer’s guidance before changing settings.
eShift can now skip several gears
The update also expands eShift, Bosch’s umbrella for compatible electronic shifting integrations. Multi-gear changes can reduce repeated inputs when the gradient changes quickly, particularly on an eMTB where speed and cadence can rise sharply once the trail opens out.
That does not remove the need to ease pedal pressure during a shift. A motor can put considerably more load through the chain than an unassisted rider, so smooth timing remains important for cassette, chain and chainring life. Our guide to the best cadence for an eMTB explains why a comfortable spinning rhythm is usually kinder to the motor and transmission.
The new eBike Assistant
Bosch has also added an eBike Assistant intended to answer questions within the connected ecosystem. Its usefulness will depend on the quality and specificity of the information it returns, but bringing setup and feature guidance closer to the controls could help riders understand options they might otherwise leave untouched.
Software advice should not replace a workshop inspection when a bike has a mechanical or electrical fault. If a warning persists, assistance cuts out or the drivetrain behaves abnormally, the safest route is still an authorised dealer with the correct diagnostic tools.
What UK riders should do before updating
- Charge the phone and eMTB battery sufficiently before starting.
- Keep the phone close to the bike and maintain a stable data connection.
- Read the compatibility notes shown for the individual bike.
- Record any customised riding-mode settings that matter to you.
- Test changed assistance or shifting behaviour on a quiet, familiar trail before relying on it in technical terrain.
As with the existing Bosch stolen-bike marking feature, the value of the update comes from how well the connected functions fit normal ownership rather than from novelty alone. Flow 1.36 looks most useful for riders who already use Extended Boost or a compatible eShift transmission and want those functions to feel more integrated.
Electric MTB UK verdict
Bosch eBike Flow 1.36 is a refinement update rather than a new motor launch, but the changes are relevant to real trail use. Easier Extended Boost management, broader eShift control and clearer in-app help should reduce the distance between a bike’s software features and the rider trying to use them. Compatibility remains the key detail, so check the options presented for your exact bike before expecting every function.