Project bike from e-scooter and vanmoof parts

[Itzigerstee]

Hi, I’m new to the forum and total noob when it comes to building electric bikes, so I hope you’ll bear with me. I’ve been reading a lot online and trying to learn, and as a first project I wanted to go with using parts I already had.

I’m trying to use the battery, controller, display and other parts from an old electric scooter, with the motor of an old Vanmoof bike and I have an interesting problem. It kinda works, but to activate the throttle, I have to first spin the wheel backwards for a moment.

The electric scooter I’m using as a donor was a Revoe Revolt R.

• 36V rear motor on an 8-inch wheel
• Brainpower motor controller (36V, 250W)
• Battery: 36V, 7,5Ah/270Wh
• Display unit: S886

The bike I’m mounting this on is an old Vanmoof electrified S from 2017. I’m only using its frame and motor, for now.

• 36V, 250W front hub motor

As a first test, I connected everything (the connector of the Vanmoof motor is the same as the connector on the scooter’s motor), but the motor activated only when I first gave the front wheel a little push backwards. Once the throttle was activated, the wheel spun forwards.

Normally, with the e-scooter, you would push it forwards to activate the electric throttle. I’m guessing it could be some pinout issue.

Possible ideas/solutions:
- The connector for the motor is symmetric and I wonder if flipping it could work (or would it damage the motor). It's a round 9-pin connector, with 8 pins in a circle and one in the middle. It has a black arrow on the side, showing the correct way to connect it (matching the arrow on the male cable connector).
- Through the P-settings of the e-scooter, I could try to disable the "push to activate" function.

 

[amberwolf]

If the scooter required you to push it forwards, it's going to require that for any system you use it on. It's probably a safety feature to prevent runaway operation. If it's a feature you can turn off, then doing so would allow you to start without that.

If you have to move the wheel backwards, its' probably a geared hubmotor, and so it only engages the motor from outside by moving the wheel backwards, but the motor only moves the wheel forwards and can't move it backwards (internal freewheeling clutch).

Otherwise, if you want to start without pedalling forward (or pushing the bike backwards) first, you'll probably have to buy a controller that works the way you want and has all the features you want, at the right battery voltage, that comes with the screen you want (your screen/controller probably only work with each other), at the right current to run your motor the way you want but no higher than what your battery is capable of (so probably no higher than the 7A or so your BP controller limits to), so you don't damage your battery.

Aside from that, to be sure things work correclty you'd need to know (test, trace out, etc) what the actual wiring is of the connectors for the controller and motor. Just because they are the same type doesn't mean the wires are the same, and it is possible to damage parts, especially hall sensors. Even if nothing is damaged, the phase/hall wiring pattern / combination may be wrong for your motor / controller combination, and you may have to experiment with the 36 possible combinations of phases and hall signals to find one of the three forward / three reverse combinations there are.

Without working hall sensors, most controllers that *can* run sensorless (fallback to that when they fail) don't always start from a stop without the motor already moving a little bit.

 

[Itzigerstee]

Thank you very much for your detailed answer, so informative! Thanks!