PearTune MSO 4.0 Tuning kit for Bosch Smart System CX Gen4 and Gen5 with Rim Magnet only

The device is fully compatible with the BOSCH SMART System Performance Line CX Gen4 and Gen5 motors and all displays available on the market for these engines such as Kiox 300, Kiox 500, Purion 200, Intuvia 100, Remote Control etc. Fully compatible with the latest Bosch SW update 04/2026 | Version 19.24.0 Also fully compatible with the GPS module from Bosch: Bosch connect module The PearTune chip is also fully functional using the original Bosch E-BIKE FLOW APP, including enabling the transfer of diagnostic data

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 tuning kit can be activated directly on your bike’s display. After pressing the 'WALK' or '+ - + -' buttons, from now on you will be able to ride at a speed of 25 mph (40 km/h) and even up to 31 mph (50 km/h)!

To deactivate the tuning kit, press the 'WALK' or '+ - + -' buttons again. Your e-bike will then work the same as before installation of the chip.

Displaying values

When riding with the chip on, the e-bike display correctly displays the actual speed up to 22.9 km/h. After exceeding this value, the actual speed is displayed on the last two digits of the display, for example: 23.3 corresponds to a speed of 33 km/h, 24.2 corresponds to a speed of 42 km/h, etc.

Service menu video:

The PearTune MSO 4.0 can be activated or deactivated anytime during the ride by short-pressing the LIGHT/WALK button or [+ -] buttons. Original function of these buttons remains unchanged. After activating PearTune - you will be able to ride at a speed of 25 mph (40 km/h), 31 mph (50 km/h) and even more than 37 mph (60 km/h)!

Activation/Deactivation can be done in two ways:
1. by starting the WALK function (press the MINUS button for 1-2 seconds until the first digit 9 of the WALK function countdown is displayed, then you must release it immediately (before the number 8 is displayed)

2. or by pressing the – + – + buttons (i.e. 4 presses) , start from the TURBO assistance mode with the MINUS button .

Chip activation is indicated by the display of 19 km/h instead of the current speed for 2-3 seconds. Chip deactivation is indicated by the display of 12 km/h instead of the current speed for 2-3 seconds. Calibration is performed completely automatically when the chip is first turned on or off.

The tuning chip for e-bikes with the newest Bosch Gen4 and Gen 5 CX motor with Smart System and Rim Magnet.

When connecting Tuning Kit to an e-bike you will find connectors colored to make installation very simple. We have prepared detailed instructions and videos 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 Peartune 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:

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

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

Peartune products are thoroughly tested and we stand by their quality - Peartune 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.