SpeedBox 1.5 B.Tuning for Bosch Performance Line SX – Rim Magnet
The SpeedBox 1.5 B.Tuning is a Bluetooth-enabled tuning chip designed for selected Bosch Performance Line SX motors fitted with a rear-wheel rim or valve magnet.
It removes the standard 25 km/h motor-assistance limit and connects the e-bike to the SpeedBox Connect app, allowing compatible settings and riding information to be accessed from a smartphone.
Important Motor Mounting Check
This SpeedBox version is designed specifically for Bosch Performance Line SX motors mounted using two diagonal screws.
Compatible motor models:
Bosch BDU3144
Bosch BDU3145
Check the motor model and screw arrangement carefully before ordering. Other Performance Line SX motor versions may require a different SpeedBox model.
Key Features
Integrated Bluetooth
Connect the SpeedBox to your smartphone using the SpeedBox Connect app.
Compatible app features include:
Activating or deactivating tuning
Setting a custom assistance limit
Viewing riding information
Saving trip data
Installing compatible SpeedBox updates
Three Activation Methods
Activate or deactivate tuning using:
The SpeedBox Connect app
The WALK function
The + – + – button sequence
Always activate or deactivate tuning before or after riding, never while the bike is moving.
Preset Assistance Limit
The SpeedBox is factory set to provide motor assistance up to 35 km/h on bikes with EU software.
Do not increase the preset maximum above 35 km/h.
Straightforward Installation
The SpeedBox connects directly to the motor using compatible connectors.
Detailed fitting instructions and an installation video are available to help guide you through installation and removal.
Compatibility
Compatible Motors
Bosch Performance Line SX
Motor model BDU3144
Motor model BDU3145
Motors mounted using two diagonal screws
Bikes fitted with a rear-wheel rim or valve magnet
Compatible Displays
Bosch Kiox 300
Bosch Kiox 500
Bosch Intuvia 100
Bosch Purion 200
Bosch Purion 400
Compatible Control Units
Bosch LED Remote
Bosch Mini Remote
Bosch System Controller
Not Compatible With
This SpeedBox is not suitable for:
Performance Line SX motors mounted using two upper screws
Bosch Performance Line CX motors
Fifth-generation Bosch CX or CX-R motors
Bikes fitted with a traditional spoke-mounted speed magnet
Bosch ABS systems
Enviolo Automatiq systems
Check the motor model, magnet type and mounting arrangement before ordering.
Technical Specifications
Factory-set maximum assistance speed:
35 km/h for EU software or approximately 22 mph for US software
Bluetooth:
Yes
SpeedBox Connect compatibility:
Yes
Custom assistance limit:
Adjustable through the SpeedBox Connect app
Activation and deactivation:
SpeedBox Connect app, WALK function or + – + –
SpeedBox updates:
Yes
Minimum distance before installation on a new bike:
10 km
Speed Display Information
While tuning is active, the e-bike display may show a value approximately 10 km/h lower than the actual riding speed.
Compatible riding information can be viewed through the SpeedBox Connect app.
For bikes using US software, the actual assistance limit after activation may be approximately 28 mph. Displayed values may differ.
Recommendations for Reliable Operation
To help ensure reliable operation:
Leave the e-bike switched on after each ride until the distance recalculation countdown has finished.
During short stops, keep one foot resting on a pedal to help prevent the countdown from starting.
During longer stops, allow at least part of the countdown process to complete.
Do not disconnect the display before the countdown has finished.
Activate or deactivate tuning only before or after riding.
Do not activate or deactivate tuning while the bike is moving.
Do not increase the preset maximum assistance speed above 35 km/h.
Software Update Warning
Do not update the Bosch motor, display or Smart System software while the SpeedBox is installed.
Disable automatic software updates where possible. Manufacturer software updates may affect compatibility, cause operating faults or increase the risk of tuning detection.
Installation on a New E-Bike
Before installing or activating the SpeedBox on a brand-new e-bike, ride the bike for at least 10 km.
This allows the motor and electronic system to complete their initial setup.
Warranty Information
Installing or using a tuning chip may affect the e-bike manufacturer’s warranty.
Faults caused by Bosch motor, display or system software updates may not be covered by the SpeedBox product warranty.
Important Legal Notice
Installing this product may cause your e-bike to no longer meet the legal definition of an electrically assisted pedal cycle.
A modified e-bike must not be used on UK public roads, cycle paths or other public places unless it has been correctly registered, insured and approved for that use.
This product is intended for use on private land with the landowner’s permission, where legally permitted. Use is entirely at the rider’s own risk.
Always wear suitable protective equipment and ensure that the bicycle, brakes, tyres and other components are suitable for the intended riding speed.