A boost button (also turbo button, power button or boost mode) on an e-bike is a function that allows you to activate short-term, maximum motor support at the push of a button – regardless of the currently selected support level.

Sprint mode on the Bosch Performance Line SX is an automatic assistance function that was specially developed for sporty riding - without the need for an additional button. Instead of being activated manually, the system uses cadence and pedal pressure to detect when the rider is demanding particularly high levels of power, for example when starting off on a hill or accelerating out of a bend. In these moments, Sprint mode switches on automatically and delivers particularly powerful assistance - exactly when it is needed. This intuitive response ensures a natural riding feel and gives the rider the feeling of accelerating particularly explosively under their own power, even though the motor is providing assistance in the background with maximum efficiency. Ideal for sporty riders who value dynamism but don't want to press buttons.

What does the boost button do?

• Maximum support on demand: When pressed, the motor immediately delivers full power – often 250 watts or more.

• Short-term active: The boost is usually only available for a few seconds – for example when starting on an incline, when overtaking or when starting from a traffic light.

• Regardless of the support level: Even if you normally ride in Eco mode, you can briefly activate full power with the Boost button.

Typical areas of application:

• Starting on inclines or with a trailer

• Fast overtaking in traffic

• Setting off with heavy luggage or child seat

• Spontaneous power boost off-road with e-mountain bikes

Advantages:

• More control in demanding situations

• Increased comfort when driving with a load

• Increased safety in city traffic through spontaneous propulsion

Restrictions:

• Increased energy consumption

• Only available as long as the battery provides sufficient power

• Can significantly reduce range with frequent use

Conclusion

The boost button is a practical feature for e-bikes that provides maximum motor support at the touch of a button. It's especially helpful in situations where you need to react quickly or access additional power — a little extra that often makes a big difference in everyday life.