Follow this guide for how to change the umbilical on your bike. Note that this is the general procedure - on some bikes you may need to perform additional steps and on other bikes, you may not need to perform these.

This guide will refer to two ends of the umbilical - the "Motor/Controller end" and the "Handlebar end" - consult the image attached for an explanation of which end is which (note that the "Motor/controller" end on your umbilical may look slightly different but the "Handlebar" end always looks very similar to this).

Tools Required:

  • Wire Snips

  • 2.5mm Allen Key - bikes with a BBS02/BBSHD Motor

  • Philips Screwdriver/T9 Head Screwdriver - Bafang Ultra Motor

  • A "Guide Cable" - this could be some bike brake cable, bike shifter cable, twine, a thick guitar string or many other possibilities! They must be strong, fairly thin and long enough to go from your bike's controller to outside the head tube at least 2 feet/600mm.

  • Electrical tape or another strong tape to secure wires together temporarily

  • Your replacement umbilical

Step 1

  • Remove your bike battery and discharge any excess electricity from the system by turning on the display with no batteries on the bike. Leave your bike battery disconnected throughout this process.

Step 2

This can be different for other bikes depending on where your controller is mounted. If it is mounted on the back of the seat tube like in the first image then you can skip this step. If your controller is in the bottom bracket area of the bike select your bike model or motor for how to open this compartment.