Tutorial: Retrofitting a Bosch system controller with display

Is your ebike equipped with a Bosch System Controller? It has a clean look and is often perfectly suitable for a quick ride. But as soon as the tour gets longer, you may find yourself missing precise data on range, speed, etc. The best thing about the Bosch Smart System is that you can expand your bike like building blocks. You can easily expand your System Controller with a Bosch Kiox 300, the larger Bosch Kiox 500, or the Bosch SmartphoneGrip. In this tutorial, you’ll learn how to upgrade your cockpit.

Step 1: Which parts are required for retrofitting
Step 2: Laying the display cable
Step 3: Mounting the display holder & retrofitting the display

Tutorial as video:

Step 1: Which parts are required for retrofitting

Before you start retrofitting, you need to choose the right components. Depending on your desired setup, you will need:

Display: A Kiox 300 or Kiox 500 or the SmartphoneGrip.
Mount: A suitable Bosch display mount (cable exit at the front or rear) and a Bosch one-arm mount.
Control unit: If you want a thumb control in addition to the control on the top tube, you can retrofit the Bosch Mini Remote. This will be connected wirelessly via Bluetooth.

Cable options:

Two-cable solution: This solution is particularly relevant for older ebikes with Smart System (before 2024). An additional, short display cable connects the system controller on the top tube to the display mount on the handlebars. The existing motor cable is simply rerouted from the controller to the display.
Y-cable solution: Especially recommended for ebikes from model year 2024 onwards. The Bosch Y-display cable connects the motor, system controller and display directly. This ensures a clean look but requires access to the motor compartment.

Step 2: Laying the display cable

Guide for the two-cable solution

The first step is to remove the Bosch System Controller from the top tube. To do this, carefully unscrew the corresponding mounting screw. Once this is done, the control unit can be removed from the top tube and the display cable connected to the system controller can be disconnected. The cable disconnected from the System Controller must now be routed to the handlebars. If your ebike has appropriate cable guides and pre-made openings in the headset, this step is not particularly challenging. If you do not have such features at your disposal, a little skill and patience will be required. Next, use the shorter display cable. You should try to estimate how long this needs to be beforehand. To be on the safe side, choose a slightly longer cable so that it really reaches the control unit in the top tube. Depending on the design of your ebike, this cable is routed through the stem or headset to the system controller in the top tube, where it is connected to the free socket. Once you have connected the cable to the System Controller, insert it back into the top tube. Make sure you don’t forget the seal during installation.

Pull the cable from the system controller

Guide for the Y-cable solution

When retrofitting the display via a Y-cable, plug the single end directly into the display port on the motor and route it inside the frame towards the system controller and handlebars. This option requires partially removing the motor from the frame so that you can access the ports. In addition, the battery must be removed in order to route the display cable through the down tube to the front. Route the cable inside the frame. At this point, it becomes clear that this solution is ultimately the cleaner one. However, it does involve a much more complex installation. As already mentioned, the shorter end of the Y-cable is plugged into the System Controller, while the longer end is routed forward to the display mount. Finally, all that remains is to connect the two cable ends to the respective components.

Step 3: Mounting the display holder & retrofitting the display

Now you can mount the display mount together with the display holder on the handlebars. When purchasing the mount, make sure that the cable outlet of the display mount points forward in the direction of travel or backward toward the ebike. This affects the direction in which the cables ultimately point.

Now it’s time to get down to the details. Simply plug the two cables into the display mount. You don’t have to worry about the order: It doesn’t matter which cable goes into which of the two slots. Once the cables are in place, attach the display holder and mount to your desired position on the handlebars and screw it tight. Now the big moment has arrived: You can attach your Kiox display or SmartphoneGrip.

Safety tip: Want to protect your display from theft? You can screw a display lock onto the back of the mount. You can see how exactly this works in detail in our video on installing the Bosch Kiox 300.