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

DESIGNED FOR:
Performance Line SX motors of 4. Gen
(Motor Models BDU3144)
(Motor Models BDU3145)
Mounted with 2 diagonal 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:
Performance Line SX motors of 4. Gen (Models BDU3144, BDU3145)
E-bikes that have a magnet attached to a valve (Bosch Rim Magnet)
The current Bosch software version
Not compatible with:
Standard magnet
ABS system
SpeedBox App

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

SpeedBox 1.5 for Bosch SX (Smart System + Rim Magnet)
SpeedBox 1.5 is a high-performance tuning chip designed for Bosch Performance Line SX motors (Gen4) with Smart System and Rim Magnet configuration. It removes the factory speed limiter, allowing riders to enjoy unrestricted e-bike performance while maintaining compatibility with the latest Bosch software.

Key Features
Compatible with Bosch Gen4 SX motors (BDU3144, BDU3145)

Designed for e-bikes using Bosch Rim Magnet (valve-mounted)

Maximum speed: unlimited (recommended up to 35 km/h)

Simple activation via WALK assist or button sequence (- + - +)

No need for magnet simulator positioning

Clear indication of tuning status via display (3.5 km/h active / 2.5 km/h inactive)

Correct distance tracking after countdown process

Easy installation using original connectors

How It Works
SpeedBox 1.5 is activated by briefly pressing the WALK assist function (holding the “–” button). The display will show 3.5 km/h, indicating that tuning is active. You can now ride beyond the standard 25 km/h limit. To deactivate, repeat the WALK assist activation—your display will show 2.5 km/h, and the motor will return to its original settings.

For e-bikes without WALK assist enabled, tuning can be toggled by pressing the - + - + button sequence. Speed limit adjustments (up to 99 km/h) can be made using a specific mode-switching pattern. The last selected limit is saved after 15 seconds of inactivity.

After each ride, allow the countdown process to complete (display shows 0.0 km/h) before turning off the bike or removing the display. This ensures accurate distance tracking and proper system reset.

Installation
SpeedBox 1.5 uses original Bosch-compatible connectors for secure and straightforward installation. Detailed instructions and video guides are available. Disassembly is equally simple. If installing on a new bike, ride at least 10 km before activating the tuning.

Important installation note: Connect male and female connectors in the direction of the lock. Do not rotate connectors during connection.

Compatibility
Compatible with:

Bosch Performance Line SX motors (BDU3144, BDU3145)

E-bikes with valve-mounted Rim Magnet

Current Bosch software versions

Not compatible with:

Standard magnet setups

ABS braking systems

SpeedBox App (use SpeedBox 1.5 B.Tuning for app integration)

Legal & Safety Notice
Use of SpeedBox products may be restricted by law in some countries. Modified e-bikes are not permitted on public roads, cycle paths, or public spaces. Use is limited to private property and at the rider’s own risk. Installation may void your e-bike’s warranty.

Recommendations:

Do not update your e-bike’s firmware

Disable automatic updates in the eBike Flow App

Always wear protective gear

Do not activate/deactivate tuning while riding

Avoid exceeding 35 km/h to minimize error codes

Product Fitment