AMX Controller Replacement

Before you start

This is a guide on how to replace your AMX Controller. Do not attempt this unless you've been advised to from Analog Motion.

Why might my controller require replacement?

The AMX controller is the brain of the bike. It turns battery power, into motor rotation. It is situated on the AMX frame below the battery and attached to the battery mount.

Reasons the controller might require replacement include:

  • Damaged physically when the bike falls or comes into contact with an object. Even a small area of damage can affect the weatherproofing of the controller.
  • Power surge. if a connector comes loose, or is disconnected when the battery is connected and powered on this can cause immediate and catastrophic failure of the controller. Its improtant to follow the manual when disconnecting connectors such as removing the rear wheel.
  • Manufacturing fault. AKA it never worked. Thankfully, this is extremely rare (less than 1 per 1500 bikes)

The Guide

This is a rather long operation, we recommend to find a well lit space and make yourself a cup of tea or coffee.
If you need to order a replacement controller, click on the button below

Tools needed

- 2.5mm Hex Key

- 4mm Hex Key

- 19mm spanner

- A bike wheel spoke (or a tiny hook, of you don't have any you can modified a coat hanger to make one, see picture below)

First steps

The first thing you want to do is to remove the battery

If you don't have a bike stand you will need to place your bike upside down so it's much easier to work on. If you do so, make sure you rotate the display inward so you won't damage it.

Use a 2.5mm Hex Key to loosen the display clamp.

Then simply rotate it so it won't touch the ground when you place your bike upside down.

If you have an AMX CLASSIC follow below, if you have an AMX STEP, click here.


1. Getting all the cables out

The first step is to get all the cables out.

Start by disconnecting the motor cable

Using the spoke, start gently pulling out the cables one by one.

Here is the list of cables:

  • Rear brake cable
  • Motor cable
  • Pedal sensor cable (flat cable)
  • Rear light cable (the one with a spiral cable) and front light cable, which are both connected to the Light Controller
  • Controller loom

Once you got everything out you can disconnect the controller loom connector, the pedal sensor cable and the light controller connector.

Make sure your cables connectors stay out of the frame when you disconnect them, if they go back in the frame it will be difficult to fish them out again.

2. Remove the AMX Controller

Remove the battery.

Unscrew the two controller bolts with the 4mm hex key.

Gently pull out the controller upward, the rubber grommet will likely come out with the cable (it's ok you can place it back later).

Depending on which AMX model you have, you may have to remove the rear wheel and the kickstand to get the motor cable out of the way.

You can then replace the controller, make sure you slide the grommet over the cables before you start threading them down the hole. Slide down the cables gently one by one, see picture below for cable identification.

It is preferable to take the cables one by one from the top hole, specially the loom cable as it will be easier to re-connect it. If you accidentally lose a connector inside the frame you can use the technique in this article to get it back.

Reconnect everything (you can just tuck in the accessory cable as it is not used on the AMX yet), test if it is working by inserting the battery and connecting the display. Then move onto the next step.

3. Tidy up

Gently tuck all the cables back inside the frame, start with the big ones (Controller, Light Controller, then Pedal Sensor cable, Motor and Rear Brake cable should go last.

See the picture below to see how it should looks like

Once you've put everything back in place you can re-connect your motor cable, make sure the arrows aligns and that the cable goes all the way to the line.

You're all done!


1. Getting the motor cable out

Start by untightening the two wheel bolts with a 19mm spanner

Using pliers or scissors, carefully cut the cable ties that hold the motor cable

Carefully disconnect the motor cable

You can now slide the rear wheel off and put it aside

If you have mudguards you will need to unbolt the lower mudguard bolt using a 4mm Hex Key

If you have a kickstand you will need to remove it using a 8 mm Hex Key

You can then free up the motor cable

2. Give the cables some slack

Give your front loom cable some slack, the loom cable is located in the front of the bike next to the handlebar

Once you found it, gently push it in into the downtube hole, you can do the same with the rear brake cable (you want to push them in by a few centimeters)

Once you've gave then enough slack, you should be able to get slack on the bottom of the downtube hole

3. Free-up the Controller

Unscrew the two controller bolts with the 4mm hex key. Put the bolts aside (don't loose them!)

You can gently and slowly start pulling out the controller, do not pull out completely, just enough to have a bit of cable slack

4. Getting the cables out

Using the spoke, start gently pulling out the cables one by one. Focus on the smaller cable, pedal sensor and light controller cable, see pics below for identification

Here is an overview of the cables and their names

You can then disconnect the pedal sensor and the light controller cable, once disconnected pull them out from the downtube top hole

It is easier to get the loom cable from the top hole, do it by gently pulling on the cable from the hole on top of the downtube.

Once it is out, disconnect it

You can also pull the motor cable out from the downtube top hole

You should have your controller out of the frame now. Make sure you mark your controller and put it aside, as you don't want to mix it up with the replacement one.

Make sure you remove the grommit and place it on the new controller

5. Quick test

Before you reconnect everything, you might want to perform a quick chekc to see if the controller is working, re-connect all the cables from outside the frame, place the rear wheel losely. Place the battery in, turn the display on and try to use the walk assist by pressing the minus button on the display (<), that should start the motor slowly. Try the pedal assist by turning the pedals and see if the speedometer works on your display. Turn the lights on and off. If all the functions are working you can move onto the next step.

6. Reconnecting the cables and placing them in the frame

Thread the motor cable throught the hole

Reconnect all the cables one by one and once re-connected push them back into the hole, start with the loom cable and move onto the smaller cables

Some of the smaller cables are easier to connect by pushing them through the controller top hole and catch it from the hole underneath the frame, re-connect and tuck it back in (see picture below)
If you accidentally lose a connector inside the frame you can use the technique in this article to get it back.

6. Attaching the controller

Now that you've re-connected everything, put the grommit in place, you can use a small hex key to force it into the hole, there is a groove on the grommit so once you've pushed it in it will stay in place.

Place the two 4mm bolts back in place. You can now place back the wheel, re-connect the motor cable, (make sure you put new cable ties to hole the motor cable in place).

You're done!

How did we do?

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