RadCity Step-Thru Controller Replacement Guide

The RadCity Step-Thru controller can be replaced in the unlikely event it is damaged or determined to be non-functional by Rad Power Bikes Product Support. Follow the steps below to replace the controller.

Tools Needed:

  • 4 mm Allen wrench
  • Phillips head screwdriver
  • Short Phillips head screwdriver
  • Flat head screwdriver
  • Flat side cutters
  • A few zip ties
  • The replacement controller
  1. Get the bike ready for maintenance. Turn off the bike, remove the battery, and press MODE to discharge remaining power.
  2. Unbolt the battery mounting tray. Use a 4 mm Allen wrench to remove the three bolts holding the battery mounting tray to the seat tube of the frame and set aside. Angle the mounting tray away from the seat tube to allow access to the controller mounting bolts.

    mceclip2.png   mceclip3.png
  3. Unscrew the controller mounting bolts. Use a Phillips head screwdriver to back out the controller mounting bolts on the top mounting bracket. Use a short Phillips head screwdriver to more easily access and remove the lower mounting bolts.

    Note: Press the screwdriver into the bolt head fully and turn slowly, being careful to not strip the hardware.

    mceclip4.png   mceclip5.png
  4. Unplug all connectors from the controller. Trace the cables from the top and bottom of the controller to the connectors. Snip zip ties as needed to pull each side of the connector directly apart, without twisting, to unplug. If the wiring harness connector is partially inside the frame, turn the handlebar all the way to the right, push the cables into the upper cable opening of the frame, and gently pull the cable out of the bottom of the downtube until the connector is accessible. Use a flat head screwdriver to unseat the rubber grommet at the bottom of the downtube, if needed. Unplug the connector.

    mceclip4.png   mceclip5.png   IMG_2512.jpg
  5. Remove the controller. Recycle the part according to local rules.
  6. Locate the new controller. Locate the new controller and use the table below to identify the connectors.

    mceclip7.png  controller_connector_ID_table.PNG
  7. Install the wiring harness connector.
    1. Pass the wiring harness connector (black with 10 pins) through the opening between the chainstays, seat tube, and fender. Make sure the connector end passes through the grommet.
    2. Find the matching connector end. Align the internal notches and pins (and external arrows) and press directly together, without twisting, to connect.
    3. Double-check that the connector is secure and gently push the connector into the downtube.
    4. Turn the handlebar to the left so the wheel is pointing directly forward. This will help the connector move into the proper position inside the downtube.
    5. Reinstall the rubber grommet.

      mceclip9.png   mceclip8.png    mceclip10.png
  8. Plug in the remaining connectors. Pass the connector ends through the opening between the chainstays, seat tube, and fender. Locate each connector's matching end. Align the internal notches and pins (and external arrows) and press directly together, without twisting, to reconnect.

    mceclip11.png   mceclip12.png
  9. Check that all cables are free from moving parts. Replace any snipped zip ties and trim them to be flush and smooth. Rotate the cranks to make sure all cables are secure.

    mceclip15.png  mceclip16.png
  10. Secure the controller to the frame. Place the controller into position between the seat tube and the fender. Carefully thread each of the four mounting bolts. Use a Phillips head screwdriver to tighten the top mounting bolts and a short Phillips head screwdriver to tighten the bottom bolts. Tighten all bolts evenly. Ensure the controller is secure and cannot move.

    mceclip20.png  mceclip21.png
  11. Bolt the battery tray to the seat tube. Use a 4 mm Allen wrench to reinstall the three battery mounting tray bolts. The mounting tray should not move once tightened securely.

  12. Reinstall the battery and test the bike fully before riding.
Caution.png If you are not confident in your ability to successfully and safely perform all steps, we recommend having the work performed or checked by a local, certified, and reputable bike mechanic.


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