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Badass Box 4 for Bafang

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by Badass
Product information "badassBox 4 Bafang"
Attention, the badassBox 4 Bafang is only compatible with the sensor shown here.

Badass eBikes proudly presents: the even better badassBox 4 Bafang

The badassBox 4 Bafang is the result of a lot of development work and works differently than our other badassBoxes due to its concept. The badassBox Bafang is mounted on the chainstay using cable ties and the speed sensor of the e-bike is unscrewed and placed on the box.

The badassBox runs on one AAA battery. You can get replacements for the supplied battery cheaply and literally on every corner. You can carry out the replacement yourself on site in a very short time without the use of tools. We recommend replacing the battery at least once a year at the start of the season. To protect against moisture and mechanical stress on the wheel, the electronics are glued into the housing with a special sealing compound and completely sealed.

We develop and manufacture the badassBox completely ourselves. Before and after casting, we check each individual badassBox to ensure it is working correctly. Customer satisfaction and quality are our top priority. We are happy to answer any question – usually on the same working day. Because of the high quality and our focus on customer satisfaction, we also offer a 1-month money-back guarantee.

Short & crisp

The badassBox Bafang is mounted on the chainstay and the speed sensor of the e-bike is placed on the box and removes the 25 km/h limit. With just a few simple steps, the e-bike is back in its untuned and therefore legal condition.

  • Contactless e-bike tuning
  • Slim, design-protected housing
  • Securing option on the housing
  • Potting compound from the automotive industry
  • Double quality control
  • Made in Germany
  • 1 month money back guarantee


The badassBox Bafang is mounted on the chainstay using cable ties (included) and the speed sensor of the e-bike is unscrewed and placed on the box.

During initial assembly, the supplied spoke magnet must be installed instead of the original magnet. Our spoke magnet works in the same way as the original magnet without the badassBox, but is necessary for the function with our patented field reinforcement when the badassBox is attached. After placing the sensor on the badassBox, the spoke magnet must be moved to the edge of the housing in the direction of the snap lock. If the spoke magnet touches the badassBox, the spoke magnet must be placed as close as possible to the badassBox and rotated by 90°. Complete!


The badassBox transmits a modified signal without contact, without an electrical connection to the motor, without interfering with the motor electronics or software, in order to exceed the speed limit. It is not necessary to laboriously open the motor. There is no risk of damage. If the badassBox is removed, the Bafang sensor is reinstalled on the chainstay and the spoke magnet is aligned with it, then the e-bike is restored to its untuned and therefore legal state.

With all the advantages, an incorrect speed and values ​​derived from it are displayed as a matter of principle. We recommend the use of GPS-related additional devices (mobile phone, bicycle computer, etc.) for more precise driving data recording.

Technical specifications

Dimensions 61 x 40 x 15mm
Weight badassBox 27 g
with battery 37 g
battery 1.5V AAA battery (IEC R03)