Help! Motor running but no power !

Debbie Lomax

Pedelecer
Jul 14, 2018
30
3
61
I have a electric trike . It is only a few months old and has been a dream ... until today . I did all my pre ride checks as usual and cycled downhill on my errands . On the way back uphill I turned my pedal assist on and could hear the motor turning over but no power . I have two batteries so when I eventually got home I tried the other battery with the same result . There are no e bike repair shops near me , so any ideas would be gratefully received .
 

Woosh

Trade Member
May 19, 2012
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16,386
Southend on Sea
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if the motor turns then there may a problem with the internal gearbox.
Have you contacted the supplier for support?
 

Fat Rat

Esteemed Pedelecer
Jun 7, 2018
1,903
726
UK
Hi welcome
I would have to agree there's obviously a proplem with the drive system
 

Debbie Lomax

Pedelecer
Jul 14, 2018
30
3
61
if the motor turns then there may a problem with the internal gearbox.
Have you contacted the supplier for support?
I have sent an email to them , it is still under guarentee , but as a newbie to electric bikes was hoping it might have been something obvious that I was missing . Thanjs guys for your comments .
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,985
Basildon
In simple terms, there isn't an easy fix. The motor will need a substantial repair that most ebike shops wouldn't want to get involved with. They just replace the motor wheel complete. Your bike will need to go back to the supplier for repair, or they might just send a motor wheel for you to install if you can.
 

Debbie Lomax

Pedelecer
Jul 14, 2018
30
3
61
In simple terms, there isn't an easy fix. The motor will need a substantial repair that most ebike shops wouldn't want to get involved with. They just replace the motor wheel complete. Your bike will need to go back to the supplier for repair, or they might just send a motor wheel for you to install if you can.
Thanks , I await their reply .
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
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The clutch is inside the disc-shaped middle bit. If you hold the very middle bit and turn the outside with your other hand, it should turn in one direction and lock in the other. If it turns both ways, you need a new one, which you can get from Greenbikekit.com. Make sure you get the right variant. There are two different middles and various numbers of teeth on the gears, though you can swap the gears over.
 

Woosh

Trade Member
May 19, 2012
19,406
16,386
Southend on Sea
wooshbikes.co.uk
to test the clutch, reassemble the motor, re-install the wheel, then turn the wheel backward to engage the clutch.
You should hear the cogs and rotor inside the motor moving and feel the resistance. Turning the wheel forward disengages the clutch and the wheel should spin freely.
It seems to me that your motor may spin backward, in the wrong direction. Do the test for the clutch first anyway.
 

Debbie Lomax

Pedelecer
Jul 14, 2018
30
3
61
I have tested the clutch , both suggested ways , and it seems fine . I had a look at the controller box for any obvious signs of damage and found none . I don't know if this is relevant but the controller states maximum 13 ah and the bike was supplied with a 15 ah battery . I am still waiting to hear from the supplier !
 

Woosh

Trade Member
May 19, 2012
19,406
16,386
Southend on Sea
wooshbikes.co.uk
if your clutch is OK, then your motor spins the wrong way round.
It's easy to fix. If your motor is sensorless, then swapping two of the three phase wires (thick yellow/green/blue wires) going to the motor is a possibility. If it's sensorless (ie only 3 phase wires, no Hall wires), swap first yellow/green, then put them back, swap next green/blue, then put them back, swap yellow and blue.
Find the combination that works best.
If it has Hall wires, then it's likely that one of the Hall sensors need replacing. You need to check them first.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
19,988
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West Sx RH
I don't know if this is relevant but the controller states maximum 13 ah and the bike was supplied with a 15 ah battery .
No it's not relevant.
The controller will be max 13a supply load.
The battery is 15ah which is a capacity rating, the more ah a battery has then the better range/distance you can travel.
 

Debbie Lomax

Pedelecer
Jul 14, 2018
30
3
61
My son just called and with his help I got the trike off the ground , to pedal whilst power on . The motor is in fact driving the wheel , only so very slowly its not noticable when I am riding it .
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
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Basildon
Yes, some of us missed that possibility. Normally, it's not possible for a controller to turn the motor backards by itself, so the question is how did it happen? Did anyone change anything, like wires or settings? If not, some controllers have what's known as self-learning, which is a procedure you do at first installation. It's activated by joining two wires, however, some people leave the wires connected, which means that it will do the self-learning procedure every time you switch on. It can't guess the direction for the motor 100%, so occasionally, it'll reverse it and then stay like that because it thinks it got it right.

In short words, have a look to see if the controller has two single wires that are joined by a connector to make a loop. They're often grey or blue, but could be any colour.
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,985
Basildon
My son just called and with his help I got the trike off the ground , to pedal whilst power on . The motor is in fact driving the wheel , only so very slowly its not noticable when I am riding it .
OK, that still sounds like slipping clutch. You can test it with the bike switched off and the wheel off the ground. When you turn the wheel forward, the wheel should be free, and when you turn it backwards you should feel the motor whirring. If you can't feel the motor, normally it means the clutch is slipping, but it can also mean that the key on the shaft that engages into the clutch centre is broken or he just forgot to reinstall it, or it fell out during reassembly.
 

Debbie Lomax

Pedelecer
Jul 14, 2018
30
3
61
No it's not relevant.
The controller will be max 13a supply load.
The battery is 15ah which is a capacity rating, the more ah a battery has then the better range/distance you can travel.
if your clutch is OK, then your motor spins the wrong way round.
It's easy to fix. If your motor is sensorless, then swapping two of the three phase wires (thick yellow/green/blue wires) going to the motor is a possibility. If it's sensorless (ie only 3 phase wires, no Hall wires), swap first yellow/green, then put them back, swap next green/blue, then put them back, swap yellow and blue.
Find the combination that works best.
If it has Hall wires, then it's likely that one of the Hall sensors need replacing. You need to check them first.
The clutch seems fine , can hear motor whirring when turning wheel backwards . It is a bafang 8 fun 250w motor which I believe has sensors , not sure how to change them though .
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,985
Basildon
Ye

Yes, it does have the wires. I am struggling at the min as it is pouring with rain and although under shelter there is no room to work.
If your controller has the self-learning wires, you have to redo the self-learning procedure until the motor runs forward.

Disconnect the wires and run the motor for a few seconds.
Switch off the bike and disconnect the battery.
Attempt to switch on the display without the battery connected. You might see it flash.
Connect the battery, join the self-learning wires, lift the motor wheel and switch on. You might see the motor turning by itself.
If it starts to turn forward, switch off then disconnect the self-learning wires. Switch on again and it should be OK.
If the motor doesn’t turn by itself, see which way it turns when you throttle or pedal. If it still goes backwards, go back to start and try a few times more until it goes forward.
 

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