SpeedBox 1.3 for Bosch Gen4 (Smart System + Rim Magnet)

What does this Tuning Kit do?

SpeedBox 1.3 for Bosch is a tuning chip that removes the speed limiter on your e-bike. With this chip you can ride faster and enjoy the full potential of your Bosch motor.

How does Speedbox work?

The tuning kit manipulates the speed signal without altering the motor's power relative to pedaling speed. This guarantees a smooth motor control without speed limit interruptions. Depending on a tuning kit, some determine when assistance stops, while others remove the restriction entirely for continuous support. However, the achievable speed mostly depends on the eBike model. Achievable speed can be calculated using a simple formula:

Speed = Cadence [rpm] * Wheel circumference [mm] * Front Chainring Teeth / Rear Chainring Teeth * 60 [min/h] / 1.000.000 [mm/km]

After installation, activate the chip via your e-bike’s control unit. Use the WALK assist function (short press of the “-” button). The display will show 3.5 km/h (2.2 mph) and assistance will be unlocked up to 35 km/h. You can set your own speed limit up to 99 km/h, but we recommend not exceeding 35 km/h to minimize the risk of error codes.

To deactivate the tuning, briefly activate WALK assist again (short press of the “-” button). Your e-bike display will show 2.5 km/h (1.6 mph) and the speed limit will reset to 25 km/h. Your e-bike will then work the same as before the tuning installation.

SpeedBox also works on e-bikes without an enabled WALK assist function. In that case, you can activate/deactivate tuning by switching between two assistance modes twice, i.e., pressing - + - +.

You can set the maximum speed limit by switching the modes from TURBO three levels down and then three levels up: eMTB - TOUR+ - ECO - TOUR+ - eMTB - TURBO. The current speed limit will then be displayed. The maximum assistance speed can also be switched by briefly activating WALK assist or by turning the rear wheel 360°. The value of 2.5 km/h corresponds to a limit of 25 km/h, 3.0 to 30 km/h, 3.5 to 35 km/h, etc. The last displayed limit will be saved after 15 seconds of inactivity.

After finishing the ride, leave the bike on until a value of 0.0 km/h is displayed. During this process the remaining time will be shown. Then it is safe to turn off your bike. Do not remove the display to lock the e-bike until SpeedBox finishes the countdown.

Activate/deactivate the tuning before the ride (when the e-bike is standing still), not during riding!

Which Speedbox Tuning Kit do I need?

This tuning kit is compatible with Bosch Smart System Gen4 Performance line CX, Performance line CX race, Performance Line Speed motors, BDU374Y, BDU376Y with Rim Magnet with the drive unit software versions up to 20.27.0.

How to install this Tuning kit?

When connecting Tuning Kit to an e-bike you will find connectors colored to make installation very simple. We have prepared detailed instructions to make installation easy for you. Disassembly of our tuning kit is just as easy. If you have any troubles with installation or disassembly, do not hesitate to contact us. If you are planning to install Speedbox on a brand-new bike, make sure you ride it for at least 0.6 miles (1 km) before the tuning kit is activated.

Installation Guide:

Important legal note!

Please note that the operation of this type of modified electric bikes on public roads may be against the law in some countries. The manufacturer takes no responsibility for damages resulting from the use Speedbox products. Electric bikes equipped with Speedbox products are not allowed to be used on public roads, cycling paths and public places. Electric bikes equipped with Speedbox products can be used exclusively on private property and entirely at one’s own risk. The use of Speedbox may void the warranty of your ebike.

We strongly recommend using other safety features and protective gear to prevent injuries in higher speeds.
Speedbox Products are thoroughly tested and we stand by their quality. Speedbox provide 2 years warranty to all their Products!