The other day my Bafang 250W front motor from Sunlova started to emit some ugly sounding knocking noises. This has happened a couple of times before when the detachable power connector from the control box to the front wheel has been pulled nearly apart. That can happen when the handlebars turn almost 180 degrees and the bike is on the centre stand.
A bit of fiddling with the power cable seemed to fix the problem. But when I started my return trip some hours later, I had no assistance from the motor at all.
On closer examination I found that the insulation on the power cable had worn through causing a short circuit. There is a sharp edge where the front fender is attached to the fork. Poor routing of the cable on my part!
The symptoms are:
When I turn on the battery the lights on the throttle go on, but as soon as I twist the throttle or turn the pedals (in Pedelec mode) the lights go out. Sometimes there is a jolt like the motor is getting fed a little power. Not enough to turn the wheel.
When I spin the front wheel by hand it rotates freely in the driving direction.
Rotating it backwards gives different results depending on whether the power cable is connected to the front wheel or not.
With the cable connected and the battery switched off, there is a heavy, “notchy” resistance.
With the cable disconnected the backward motion is smooth and even and the resistance and sound is more like that of an old fashioned bottle dynamo.
I got the kit installed in late January and have done 900km since then. Quite proud of myself. My annual bike mileage used to be less than 100km!
I obviously will have to get some new parts from Sunlova/8Funbike.com . Based on the above description do you think that a new control box and power cable would suffice? My kit is of course the old style kit with the thick pedelec sensor. I don’t think the parts are interchangeable with their new kit!
A bit of fiddling with the power cable seemed to fix the problem. But when I started my return trip some hours later, I had no assistance from the motor at all.
On closer examination I found that the insulation on the power cable had worn through causing a short circuit. There is a sharp edge where the front fender is attached to the fork. Poor routing of the cable on my part!
The symptoms are:
When I turn on the battery the lights on the throttle go on, but as soon as I twist the throttle or turn the pedals (in Pedelec mode) the lights go out. Sometimes there is a jolt like the motor is getting fed a little power. Not enough to turn the wheel.
When I spin the front wheel by hand it rotates freely in the driving direction.
Rotating it backwards gives different results depending on whether the power cable is connected to the front wheel or not.
With the cable connected and the battery switched off, there is a heavy, “notchy” resistance.
With the cable disconnected the backward motion is smooth and even and the resistance and sound is more like that of an old fashioned bottle dynamo.
I got the kit installed in late January and have done 900km since then. Quite proud of myself. My annual bike mileage used to be less than 100km!
I obviously will have to get some new parts from Sunlova/8Funbike.com . Based on the above description do you think that a new control box and power cable would suffice? My kit is of course the old style kit with the thick pedelec sensor. I don’t think the parts are interchangeable with their new kit!
