Motor or controller

[trevorjsaxby]

Hi, I have just bought a Blue Spider scooter. 36 Volts 200 watts. The problem I have is that if I lift the motor wheel off the ground the motor spins but when I put it back on the ground it doesnt power the bike, seems as though it doesnt have enough torque. Does anyone know what the problem may be. Thanks

[Bikemad]

Hi and welcome Trevor,

I would start by checking the obvious:

• Make sure the batteries are fully charged.
  
• Use a voltmeter to see if the battery voltage decreases dramatically under load.
  
• Check the wiring, and make sure all the connections are good and tight.
  

I don't know what else to suggest, but if it's not a battery, wiring or connector problem, it will probably be a fault with either the hubmotor or the speed controller.

Sorry, but that's the best advice I can offer.

Alan
 

[trevorjsaxby]

Hi Alan
I`ve checked the batteries and even tried a brand new set.
When I attached the voltmeter the voltage dropped by about 2 volts
The wheel tries to spin but just doesnt have enough ooomph.
It will get me about 10 feet and then gives up
As you say it must be the controller or motor but I don't know how to test either
The motor has 8 wires going to it so its not simply a matter of connecting 36 volts to it
Thanks anyway
Trev

[Electrobent]

and even when everything points to the wheel being at fault, it can still be the controller (don't ask how I know this.)

Double Check all your connections. 

What kind of controller is it?

[trevorjsaxby]

Hi Sorry for the delay in getting back. The controller has no markings on it other than "36V 200" I thought this would probably be a good place to start so made enquiries as to a replacement, the motor is brushless as it has hall sensors. I have not been able to obtain a new controller from anywhere but if and when I do I will post the result, Many thanks for your help. PS I have rechecked all the wiring and remade some iffy joints but still have the vsame problem. Thanks

[e-lmer]

Trevor;

If you hold the wheel back by hand and let it slowly
turn does it turn smoothly or in jerks?

If it turns smoothly it is a supplied power problem,
you are not getting 36 volts out of the batteries.

If it jerks, then there are a few possibilities.
The windings may have been melted by someone
trying to get more than 200W out of it.

You can usually test for this by measuring the AC voltage
the wheel produces when turned at a steady rate across
the main windings.  If all three possible connections
measure the same voltage, the main windings are ok.

There is a way to test the hall sensors, but I am
not familiar nor have I ever done it.