SIMPLIFIED INSTALLATION
No need to find a suitable position for the Magnet Simulator

DESIGNED FOR:
Performance Line SX motors of 4. Gen
(Motor Models BDU3142)
(Motor Models BDU3143)
Mounted with 2 top screws

PROPERTIES:
Maximum speed: Unlimited (max 35 km/h recommended)
Display shows:
Real speed: NO
Correct travelled distance: After the countdown process is finished
Activation/deactivation (do not perform while riding):
WALK function
- + - +
Indication of tuning activation/deactivation: YES (3.5/2.5 km/h)

Compatible with:
Power Line SX motors of 4. Gen (Models BDU3142, BDU3143)
E-bikes that have a magnet attached to a valve (Bosch Rim Magnet)
Not compatible with:
Standard magnet
ABS system
SpeedBox App

Please check your e-bike type and motor space before purchasing the product

SpeedBox 1.4 Tuning Chip for Bosch Performance Line SX (Gen4) + Smart System
Unlock the full potential of your Bosch-powered e-bike with the SpeedBox 1.4, designed specifically for Performance Line SX motors (BDU3142, BDU3143) equipped with the Smart System and Rim Magnet. This third-generation tuning chip removes the factory speed limiter, allowing for enhanced performance while maintaining a clean and simplified installation—no magnet simulator required.

Functionality
SpeedBox 1.4 enables your e-bike to suppress the 25 km/h speed limit, allowing speeds up to 35 km/h or higher. While the chip allows for unlimited speed settings (up to 99 km/h), we strongly recommend not exceeding 35 km/h to minimize the risk of error codes and ensure safe operation.

After installation, your e-bike display will not show real-time speed during the ride. However, accurate distance and ride data will be displayed after the post-ride countdown process is complete.

If you prefer to see real-time speed and ride metrics during your ride, consider upgrading to SpeedBox 1.4 B.Tuning, which connects to the SpeedBox App for live data on your phone.

Activation & Speed Settings
Activate or deactivate tuning only when the bike is stationary—never while riding.

Activation methods:

Hold the “-” button to engage WALK assist. Display will show 3.5 km/h, indicating tuning is active.

To deactivate, repeat the process. Display will show 2.5 km/h, and the limiter will reset to 25 km/h.

For bikes without WALK assist enabled, use the - + - + button combination to toggle tuning.

Speed customization:

Switch modes from TURBO down three levels, then back up: eMTB → TOUR+ → ECO → TOUR+ → eMTB → TURBO

Speed limit indicators:

2.5 km/h = 25 km/h

3.0 km/h = 30 km/h

3.5 km/h = 35 km/h

The last displayed limit is saved after 15 seconds of inactivity.

Post-Ride Protocol
After each ride:

Leave the bike powered on until 0.0 km/h is displayed.

Do not remove the display until the countdown process is complete.

For short stops, keep one foot on the pedal to prevent countdown initiation.

For longer stops, allow at least a partial countdown.

After extended rides, the countdown may take several minutes.

Installation
SpeedBox 1.4 uses original connectors for secure and straightforward installation. Connect male and female connectors in the direction of the lock—do not rotate during connection. Detailed instructions and video guides are available, and disassembly is just as simple.

For new bikes, ride at least 10 km before activating the tuning.

Compatibility
Compatible with:

Bosch Performance Line SX motors (BDU3142, BDU3143)

E-bikes using Bosch Rim Magnet (mounted on valve)

Not compatible with:

Standard magnet setups

ABS systems

SpeedBox App (unless using B.Tuning version)

Please verify your motor type and magnet configuration before purchase.

Legal and Safety Notice
Please note that operating a modified electric bike on public roads may be illegal in some countries. The manufacturer assumes no responsibility for damages or legal consequences resulting from the use of SpeedBox products.

Electric bikes equipped with SpeedBox tuning chips:

Must not be used on public roads, bike paths, or public spaces

May only be used on private property and entirely at the rider’s own risk

May have their warranty voided upon installation

Additional recommendations:

Do not update your e-bike’s firmware; disable automatic updates in the eBike Flow App

SpeedBox warranty does not cover malfunctions caused by firmware updates

Always wear appropriate protective gear

Activate/deactivate tuning only when stationary

Do not exceed speeds of 35 km/h

SpeedBox 1.4 offers a streamlined solution for riders seeking enhanced performance on private terrain. For installation support or compatibility questions, please contact us directly.

Product Fitment