Power loss and grating noise

[andyc]

Hi - I am Andy and am on my second e-bike which I have had for 3-4 years having got it second hand on e-bay its a 3E sports / mountain bike with a Ben Yuan 37v / 18AH Li-ion battery and has done me fairly well.

I now have a problem with a growling / grating noise coming from the rear hub where the motor is. There is also a severe loss of power. Sometimes this lasts for a few seconds or a few minutes and then goes and I am on reasonable power but the problem can then come back - other times there is a complete loss of power. A couple of times the power has completely shut down. I used to fiddle with where the power cable went into the hub and sometimes that would solve it for a few miles, but that now rarely works.

My guesses are a) a problem with the motor in the hub, b) a loose connection somewhere, c) the battery not holding its charge (but if so why does the power sometimes come back later on in my commute?)

I called a bike shop in Sheffield that deals with e-bikes but they wouldn't look at it as they said they wouldn't have any spare parts for a Chinese bike and that all bike shops would say the same. I don't seem to be able to find a dealer on-line - I think it was sold by one in Harrogate who then moved to N. London.

Does anyone have any advise about where to start? Or anyone who would look at it and service/repair it. I live partly in Sheffield and partly in London.

Thanks

Andy

 

[vfr400]

SYEBC in Rotherham might look at it for you. The guy in the workshop (Dale) is quite good.

Your problem is almost certainly an interruption on one of the wires in the motor cable. In particular, look at any connectors between the motor and controller. If you have the 9-pin one about a foot from the motor, check that it's pushed in all the way to the line.

Running your motor in that condition will blow your controller, so do any testing on the lowest power setting.

 

[Benjahmin]

Almost certainly a poor phase connection. Have a look at this thread:

Help! - Motor Connectors

Looks like the block/bullet phase connector for my motor is causing heat and possibly noise problems. It sits in this box on the fork, along with the hall connector. This is what it looks like now:oops: I need to replace it with either something that will fit in the box, or something...

www.pedelecs.co.uk

I had lots of grindy noise and controller would overheat on long steep climbs, this cured it.

 

[Andy-Mat]

Hi - I am Andy and am on my second e-bike which I have had for 3-4 years having got it second hand on e-bay its a 3E sports / mountain bike with a Ben Yuan 37v / 18AH Li-ion battery and has done me fairly well.

I now have a problem with a growling / grating noise coming from the rear hub where the motor is. There is also a severe loss of power. Sometimes this lasts for a few seconds or a few minutes and then goes and I am on reasonable power but the problem can then come back - other times there is a complete loss of power. A couple of times the power has completely shut down. I used to fiddle with where the power cable went into the hub and sometimes that would solve it for a few miles, but that now rarely works.

My guesses are a) a problem with the motor in the hub, b) a loose connection somewhere, c) the battery not holding its charge (but if so why does the power sometimes come back later on in my commute?)

I called a bike shop in Sheffield that deals with e-bikes but they wouldn't look at it as they said they wouldn't have any spare parts for a Chinese bike and that all bike shops would say the same. I don't seem to be able to find a dealer on-line - I think it was sold by one in Harrogate who then moved to N. London.

Does anyone have any advise about where to start? Or anyone who would look at it and service/repair it. I live partly in Sheffield and partly in London.

Thanks

Andy

Difficult problem, I cannot really help much as I have (thankfully!) never experienced such a problem. But I follow your reasoning and guessing only, I would look for a loose connection, your 2).
You will need a multimeter and how to use it, as a bare minimum.
If I had such a problem, I would dismantle it myself, and either I fix it or not, but a new rear wheel and motor is not expensive, especially if you compare the price of of a new e-bike and the cost of petrol and diesel nowadays!
So don't be disheartened....
But you need to be at least a good DIY electrical/mechanical person to take it apart with at least a chance of repairing it.
People without this knowledge should buy from a reputable shop near to where they live....
Even with such a problem "declared", your bike will still sell well on ebay to a good DIYer looking for an e-bike.
Let us know how you get on.
regards
Andy

 

[andyc]

Thanks for these suggestions. I called Electric Transport Shop in York today and they said they could probably help but have a two week wait and I am only in Sheffield for week. I also tried SYEBC and they hadn't heard of 3E and wouldn't look at it. So I have left it in London rather then cycle across London without the power assist, and am now trying to convince myself that going back to a normal bike for a few weeks should do me good! These suggestions are all very helpful. Time permitting I will look at the connector when I am back in London - its about 9" from the hub. If not I will bring it up to Sheffield towards the end of July and look at it with an electician / auto electronics friend here and/or buy a new rear wheel with a motor in and/or take a trip to York with it - though £65 just for diagnostics is a bit off putting!

Any recommendations for getting a new rear wheel with motor and roughly what sort of price does one pay?

Where is the controller located?

 

[Andy-Mat]

Thanks for these suggestions. I called Electric Transport Shop in York today and they said they could probably help but have a two week wait and I am only in Sheffield for week. I also tried SYEBC and they hadn't heard of 3E and wouldn't look at it. So I have left it in London rather then cycle across London without the power assist, and am now trying to convince myself that going back to a normal bike for a few weeks should do me good! These suggestions are all very helpful. Time permitting I will look at the connector when I am back in London - its about 9" from the hub. If not I will bring it up to Sheffield towards the end of July and look at it with an electician / auto electronics friend here and/or buy a new rear wheel with a motor in and/or take a trip to York with it - though £65 just for diagnostics is a bit off putting!

Any recommendations for getting a new rear wheel with motor and roughly what sort of price does one pay?

Where is the controller located?

To locate the controller, follow the wires from the motor to wherever they go, there you will find it.
Sadly, I cannot advise on which motor and wheel combination to buy, as I have thankfully not had the need to buy one..... Hopefully someone here has good first hand information for you.
If you are not much of a DIYer, then look around in the UK for a quality bike shop and their offerings.
Such wheels are sold on ebay, but sadly, mostly little or no support, you need to know what to do....
Just for example, this is NOT a recommendation, check here:-

E-Bike Front Wheel Motor for sale | eBay

Find great deals on eBay for E-Bike Front Wheel Motor. Shop with confidence.

www.ebay.co.uk

Remember, usually no battery included!!
I would imagine (guessing only!) that a front wheel hub motor to be the easiest of the conversions, and if your motor that is giving problems is on the rear wheel, replacing a rear wheel is easy, even moving the gear change over is easy to do, in my limited experience, due to there being standards....!
But I am fully prepared to be wrong on that score....sorry I cannot be more help.
It could be possible that one way or another, the money may be better put towards a new bike with a full guarantee....and sell the old one as defective on ebay....you may be surprised what it gets, as long as your ad is honest and well and carefully written. Plus loads of clear photos, more is better than less, bike shining and clean!
I am sure that many other members can advise you better than I on what to do..
regards
Andy

 

[vfr400]

or buy a new rear wheel with a motor in and/or take a trip to York with it - though £65 just for

Any recommendations for getting a new rear wheel with motor and roughly what sort of price does one pay?

Where is the controller located?

Don't look at a new motor yet. The problem is almost certainly not coming from the motor.

 

[Benjahmin]

Agreed.
I know it sounds really rough and there's probably a lot of vibration and you're sure it's mechanical.
But there's a really high probability that it's electrical - honest, I've been there, been through the denial. In the end it cost me about £1.50 for some connectors to cure it. Gotta be worth a shot hasn't it?

 

[andyc]

Thanks guys, very helpful - I agree its most likely to be electrical and that the connector is the first thing to go for. It will be at least a week or two before I can have a look at it - but with luck I'll find time before the end of July!