BadassBox 4 Bosch Slim-Set

Derestrict your e-bike to reach speeds up to 25mph (40km/h)

Compatible with all ebike Bosch Motors that have a specific sensor! Please refer to the sensor pictures!

Regular price£159.00

&Free Delivery Worldwide

You can save money when buying more than one tuning kit. Can be combined with other brand/type tuning kits!
Buy 2 save £4.77
£159.00 £154.23
Buy 3 save £11.13
£159.00 £147.87


- TOM E.

easy to install EASY TO INSTALL

Main Product Information

The badassBox is attached to the speed sensor of the e-bike and overrides the 16 mph (25 km/h) speed limit - you can expect to reach speeds of up to 25 mph (40km/h) , depending on the bike and gearing. Your displayed speed will be 2 times slower than your real speed. We recommend the use of GPS-related accessories for a more precise data acquisition of driving data (smartphone, bike computer, etc.).

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]

The contactless and wireless badassBox transmits a modified speed signal in order to override the speed limit of your e-bike – without interfering with the motor's electronic circuitry or software. There's no need to open the motor and there is no risk of damaging it, the BadassBox can be fitted or removed in seconds.

This tuning kit is made to fit bikes with either the Bosch Slim speed sensor on the chain stay, or with the alternative Bosch Slim speed sensor integrated into the bike, with the magnet in the brake disc.

Your sensor should look like this if it's on the chain stay:

Or like this if the speed sensor is integrated into the bike and your magnet is in the brake disc:

This order set contains everything you need to install the badassBox 4 for your e-bike with Bosch mid-motor and the Bosch Slim sensor. A quality product developed and manufactured by us in Germany.

The installation requires a small modification. Please read the installation instructions on the right before ordering!

The delivery includes the following parts:
- one badassBox 4 Bosch
- one badassBox 4 housing cover
- one AAA battery
- one spoke magnet with thumb screw
- one Slim-Adapter
- a base made of elastic foam
- one M5x10 cylinder head screw
- one washer
- four cable ties

The Bosch Slim Sensor is either mounted on the chain stay or integrated into the dropout.

Here the slim speed sensor is classically mounted on the chain stay with an adapter. There, the sensor must be freed from the adapter, the original adapter is unscrewed and replaced by our adapter.

Here the slim speed sensor is integrated near the rear axle. First, the rear wheel must be removed.

Then the sensor is removed from the bracket and mounted with our adapter at a suitable place on the chain stay using cable ties. It's now ready for use.

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 of Badass Box products. Electric bikes equipped with Badass Box products are not allowed to be used on public roads, cycling paths and public places. Electric bikes equipped with Badass Box products can be used exclusively on private property and entirely at one’s own risk. The use of Badass Box products may void the warranty of your ebike.

We strongly recommend using other safety features and protective gear to prevent injuries in higher speeds.

Badass Box products are thoroughly tested and we stand by their quality - Badass Box provides 2 years warranty to all their products.

Warranty does not cover damage resulting from eBike software updates. Remove the tuning kit before updating the software. Check with us first to ensure the kit is compatible with your updated eBike. We cannot guarantee that the kit will function the same after updates. Please exercise caution.

Compatible with all ebike Bosch Motors

Unlock the full potential of your ebike!

  • You will ride faster and experience the thrills of owning a derestricted ebike -you will love the difference!
  • Install it effortlessly - easy and fast installation!
  •  Feel safe for your e-bike and warranty - it's safe for ebike and undetectable to keep your warranty safe!

BadassBox 4 Bosch Slim-Set
BadassBox 4 Bosch Slim-Set

Quick plug-and-play installation. No setup!

  • Increase the speed limiter from original 16 mph (25km/h) up to 25mph (40km/h) speed limit!
  • Fully undetectable! After BadassBox removal there is no way to tell if it has been used on your e-bike!
  • Get after-sales support from us and a two year warranty from BadassBox!


The bike feels completely different once derestricted - it's just like a whole different bike! The rides are so much more fun now! Tuning kits are safe to your bike and every ebiker should have one installed! You will love riding your ebike with it - guaranteed!

Matt - Owner of Two Wheels Empire

What Our Clients Say About It?

Who Are We?

From Riders to Riders

In Two Wheels Empire, we trust in innovation, premium quality and sustainability - that's what our business is about. Feel assured all our ebike products are carefully selected and we stand by them: if it's on offer here at Two Wheels Empire - it's been tested and selected by our team. Riders working with us are here to help you enjoy your ebike rides!

We are here to build an Empire, of people who strive for freedom, thrills and adventure, it's about time to make the best of your rides!